Bristlenose Pleco – The Care, Feeding and Breeding of Bristlenose Plecos

Bristlenose PlecoQuick Stats

Minimum Tank Size: 29 Gallons
Care Level: Easy
Water Conditions: 6.5 – 7.5 and Soft to Medium but is highly adaptable
Temperature: 70-80 F (20-27 C)
Maximum Size: 6 inches (15 cm)

The bristlenose pleco (Ancistrus cirrhosus), also known as the bushynose pleco, has a wide distribution throughout the Amazon river basin in South America. It can be found in a variety of habitats, from shallow low oxygen floodplains, to the deep, dark waters of rivers. There are several commercially available species, but Ancistrus cirrhosus is the most common.

Bristlenose plecos are commonly known as suckerfish, and make an excellent addition to most freshwater aquariums. They are arguably the best algae eaters available – both because of the large amount of algae that they consume and their hardy, easy to care for nature.

While the common pleco can grow to the size of a river monster in a tropical aquarium, bristlenose plecos stay quite a bit smaller, and usually top out at around 6 inches. Because of this, they are a far better choice than the common pleco if you are looking for an algae eating fish.


Bristlenose plecos need a spacious tank with strong filtration. The reasons for this are simple – they need space, and they tend to be prolific poopers. Much of their life seems to consist of searching for food, eating the food, and then searching for more. Because of this, they are prodigious poop producers, and if the water isn’t well filtered, the water quality will quickly plummet.

In the wild, adult bristlenose plecos tend to hide in caves and under driftwood when they aren’t foraging and should be provided with similar hiding places in the aquarium. This can be as simple as providing a clay pot on its side, or you can provide large pieces of driftwood with overhangs that a bristlenose pleco can hide under.

When choosing a filter for them, a HOB (hang-on-back) filter is the most economical choice, and in combination with a sponge filter, it will keep the water sparkling clean . However, if you have a bit more money to spend, a canister filter is usually the best choice for most tropical aquariums.

I would strongly recommend choosing an Aquaclear Power Filter for a bristlenose pleco tank. This filter combines excellent filtration with a durable design, and it will keep your tank sparkling clear for years to come. You can also read the Aquarium Tidings Aquaclear Filter Review here.


Like previously stated, bristlenose plecos love to eat and you can provide them with a wide range of food. Their main diet should be composed of a spirulina based sinking pellet, since they tend to mainly eat on the bottom of the tank. This should be supplemented with vegetables, as they need a large amount of plant matter in their diet. A hungry bristlenose pleco will completely devour every last piece of blanched zucchini, cucumber medallions and shelled peas. They also appreciate broccoli and a wide range of other vegetables. Always remember to remove any uneaten vegetables after 24 hours to prevent water fouling.

If you are hoping to get a bristlenose pleco into breeding condition, they should be fed live or frozen foods. Their particular favorites are bloodworms and live blackworms, and they tend to ignore most other frozen and live foods. The key is to ensure that the food reaches the bottom of the aquarium, or they most likely won’t even notice it.

One thing to remember with bristlenose plecos, is that they require fiber in their diet- especially if they are consistently fed regular fish food. Some fiber can be provided through vegetables, but unless you are careful to consistently feed vegetables, they generally won’t have enough fiber in their diet to remain healthy.

There is a simple solution to providing enough fiber – just include a piece of driftwood in their tank. Nearly all species of plecos will rasp on any driftwood in their tanks, which provide them with more than enough fiber to help them stay healthy and active.

bn plecoBreeding

Bristlenose plecos are easy to breed and only usually have to be provided with a cave to spawn in – the rest they do on their own. You should always try to have more females than males, unless you have a very large tank. The males are incredibly territorial and will quickly claim a cave for breeding purposes. Any other males will then fight the male for control of the cave and given the opportunity, will indulge in quick meal of caviar (they will eat their male rival eggs).

When preparing to breed bristlenose plecos, you first need to determine if you have at least one male and female. You can determine the sex of them by simply looking at the “bristles” on their heads. Males will usually have larger bristles and they will extend to the middle of its head. Females will only have bristles around their mouth, and they tend to be much smaller than the males.

When the male is ready to breed, it will begin to excavate a cave (clay pot or overhang), and will clean off the surfaces of it in preparation for eggs. Once the male is done, he will settle in to his newly claimed cave, and wait for a female. Once a female comes by, she will inspect the cave and if suitably impressed, will decide to move into the cave and deposit her eggs.

Once the eggs have been deposited on the walls of the cave and fertilized by the male, he will push the female out the cave, and begin to guard the eggs. During this time, other females may be enticed into the cave, and the male may end up fertilizing the eggs from several different females.

The eggs will then hatch after around 4-10 days and the fry will cling to the sides of the cave until they have completely absorbed the egg sacks. During this time, the male will continue to guard the fry until they are free swimming on their own.

The fry can be feed with infusoria or powdered spirulina. After a few days they can be fed baby brine shrimp and they will also eat any available algae.

Pleco or Plecostomus?

If you are new to the hobby, you will only ever rarely hear “plecos” referred to as a plecostomus. There is a simple reason for this – it’s considered bad luck to refer to plecos by their full name. There is a belief among some in the fish keeping hobby, that if you use the full name, you will soon have a dead pleco. (I will update this page if I suffer any devastating pleco losses after daring to say plecostomus in this article.)


  1. says

    Hi there,
    I have a few questions…

    How do they mate together ?
    How long are they pregnant for ?
    As today’s date is the 14th October, how many times does it get pregnant for. ?

    • says

      They don’t get pregnant but a male bristlenose pleco will entice a female bristlenose pleco into a flower pot or cave where she will lay her eggs and he will fertilize them. The eggs are then cared for by the male until they hatch in a few days. The fry will then become free swimming a few days after that.

      This can happen relatively regularly if you provide them with good food and conditions.

  2. barbara says

    How do I get my bn to stay out of hiding long enough for me to get a good look at his bristles? He’s quickly back in hiding. I’d like to get him/her a mate, but the wrong choice could be disastrous. I put algae wafers in, and cucumber/ courgette or whatever.

    • says

      It can be very difficult to get some plecos out of hiding. If you remain completely motionless after adding food, it will often come out so it can be examined. Barring that, you can use a flashlight after you turn the lights out in the room, and you can often get a good look at it that way. I’ve used that method with some of the other nocturnal fish that I have.

  3. callum says

    I lost 2 plecos the last 2 days after saying their full name a week ago…

    But today i have just found 12 babies!!! 😀

    • says

      Take care of those babies. They can make up for you saying the full name. lol

      I know it’s a silly superstition, but years ago I said the full name and a 12 inch pleco somehow escaped my main tank and died on the floor. I haven’t said it since.

  4. Robert says

    I got 4 plecos in July as barely half an inch long so I’m guessing not very old. But how old do they generally have to be to start breeding?

    • says

      I wouldn’t go by age, since so many factors can affect their maturity. I would go by size, and most bristlenose plecos will begin to breed when they are around 3-4 inches in length. Four inches seems to be the more common size though.

  5. Anne says

    Hello, what a fabulous no-trivial-trimmings-article, thank you!

    So, I now have a 4cm fit & healthy regular bristlenose pleco. Alone in his 110L tank, Juwel sophisticated filtration system, PH 7.5, Ammonia reading 0, 26 degrees C; I have decided to stick to this type of fish only and I do not want to overpopulate, but I think he needs at least one little friend.
    My preference would be an albino pleco for variety, which I am finding difficult to source… I’m in the southwest of UK.

    There are two things I really need to know:
    1) Am I right to think I should only add one more fish? Or would three BN plecos be happy & healthy in 110L?
    2) How old / what size does a BN pleco develop its bristles so it can be recognized as male or female?

    I just want a couple of happy pet fish, no intention to breed them, definitely don’t want to see them fight…

    Thanks in advance for any advice :)

    • says

      I’m glad that you enjoyed the article. And bristlenose plecos are perfectly happy being solitary creatures. Males establish large territories, and will often fight with other males – especially in a smaller tank like the on that you have. You may be able to keep three adult bn plecos in your tank, but you have to be sure that the tank contains only one male. Also, when males are younger they are known to attack female plecos. It’s best to make sure that all of the fish are mature before keeping them together. While juvenile females are often attacked, the presence of an adult female seems to change their behaviour, and you generally only get some chasing.

      Also, in my experience the bristles begin to show on males usually when they are between 4-6cm in length. They can take a while to grow in, and the females don’t develop much in the way of bristles.

      I hope this helps.

      • Anne says

        Yes, it does help, thank you! Since loneliness is not an issue, I shall patiently wait till my pleco is mature to be sure of its gender. :)

  6. Mike says

    I’ve recently discovered that my bristlenose plecos have laid eggs inside of a piece of driftwood. I’m really excited to have the babies to care for. I was curious to know if keeping them inside the tank I currently have is ideal since they are weak and still new, or if setting up a 10 gallon tank with water and rocks from this one would be helpful to keep them isolated. They are currently in a 35 gallon with a couple other plecos and some angels. I’d like to hear your opinion on the matter. Thanks in advance

    • says

      It’s a tough decision to make whether to keep them in a community tank, or to remove them to their own tank. The problem is that it is very easy to injure or kill fry when transporting them from one tank to the other. Not only is netting out of the question, but any change in their water chemistry is likely to kill them. But on the other hand, very few generally survive in a community tank, and you will likely see most of your bristlenose pleco fry get eaten over time.

      If you do decide to move then, you will need to move them with something like a turkey baster. Using a net is just too danger with new born fry. And then the 10 gallon tank must be fully cycled – any spike in ammonia,nitrites or even nitrates will most likely wipe out the fry. Then before you place them in the tank, you will have to use the drip acclimatization method to ensure that they have plenty of time to get used to the new water chemistry. It’s difficult to do, but not impossible.

      • Mike says

        As a follow up, I did move all the eggs to a new tank. I took the whole piece of driftwood that they were in, father and all, kept it submerged for most of the transfer and they did just fine. They hatched 11/04 and I have over 80 healthy plecos. I’m going to be selling off nearly all to a local fish store but I’m having a lot of fun watching them grow and develop. Thanks for the help

  7. Ryan says

    I have a nice pair of BN and they have breed like crazy and if Plecos shouldnt be counted as a swimming fish more like an ornament then how many are ok to keep in a 40 gal tank i have well over a hundred that are a quarter inch 10mm long and everything seems ok the water is pristine and I have about 12 pieces of driftwood in it. they live on frozen fish food cubes and veggies

    • says

      The problem that you run into with bn plecos, is that the males stake out large territories and defend them vigorously. This isn’t much of a problem while they are young, but as soon as they begin to grow you’ll have some major aggression issues on your hands. For a 40 gallon tank, you should be able to get away with two to three bristle nose pleco males, and about twice that number of females. Any more than that, and you’re just asking for trouble.

  8. marie says

    Hi what do baby bn feed on as think I may have some soon when do the male bn level them on their own very new breeder

    • says

      You have a few options with bn pleco fry. You can provide rocks with lots of algae for them graze on, or you can provide powdered spirulina. They will also feed on vegetables, so you can drop a few at different places in your aquarium, but any uneaten pieces will have to be removed within 24 hours to prevent the water from fouling. Some people also provide them with baby brine shrimp, though in my experience they will be fine with some spirulina algae wafers broken up into their tank.

  9. Wanda Dority says

    Thank you so much for your article. We have a 50 gallon tank with two adult bn plecos. We were quite surprised when they laid eggs. I read all I could find, but none were specific to bn plecos. Our first batch of babies were all eaten by our angels and swordtails. Two months later they hatched out more eggs and per info I found on the web we did almost 50% water changes and they all died in one day. Seven or eight weeks later we had another batch of babies. I built a divider with a frame and plastic canvas to keep the other fish from eating them. Some got past the barrier and were eaten, but we have about 24 that are 1/2″ to 3/4″ long. Now, six weeks later we have another batch of babies. Looks to be 40+.
    You mentioned that young males will attack young females. Can they all be left together until they are ready to sell or do I need to separate them? How big might they be when I need to separate them? I had thought about moving the adult female to another tank to delay any more eggs being laid. If I understood you correctly, you said the presence of an adult female would help reduce the aggression.

    • says

      That’s great that you were successful in raising some bristlenose pleco fry.

      And most can be left together (assuming your aquarium can handle the waste load) until they reach about an inch in length. After that, you will start to experience some pretty serious aggression issues. A lot depends on the set up of your tank though. If you have a lot of plants, driftwoods, or ornaments that help to establish little territories, you should be able to get by without too many issues. If they’re all crammed together, you’ll end up with some fish with shredded fins.

      The best thing to do is to keep an eyes of them. Most stores will only buy them once they reach 1.5 inches in length, so the challenge is to have enough grow out tanks to accommodate all of the bn pleco fry.

  10. marie says

    will to night I have just seen some baby b n just like to know if I can do a tank clean up or not what the right food for babies as new to fish keeping

  11. Mykal says

    I have a small clutch of baby bn and was just wondering how big before I can move them into anther tank?? There around an inch long at the moment

  12. Kenny McEwen says

    I have enjoyed reading this forum. It has been very informative. We have a 125G long and plenty of room for my very active breeding pair. I was curious to others results because I see fry #s in the 40+ range. We lost all of the first batch. I found that out beautiful blue lobster that we had was eating all of the fry. He was emediatly sold!!! Since then we have had 3 batches. 1st there are 6 left approx <1", 2nd there are about 10 left <.5" and a 3rd a new batch discovered yesterday that are quit small. Daddy is still guarding 10+ babies and about 15 have escaped his cave. With a a total count of 25/30. This is a fairly young pair of BN purchased 6 months ago at <2" each. We had one female and two males, one being an albino(that we lost :'( and will never say their full name again!!!). Present time Moma is <3.5" and daddy is <4". With that being said. Tank mates are 10 corydoras, 6 ottocinclus, and about 45 various types South American tetras. With a PH of 6.6. The only fish large enough to eat the fry is one of my bleeding hearts is quite large for its usual size. Its about 2.5"

    With that the question is, as they start breeding is it normal for the counts to be that low or am I loosing that many fry and need to remove some other fish. I have a Malawi cichlid tank 55g, and a 16g "wide screen style" tank. That can be used. We have been so excited thus far and are okay with the few we have been successful with. However we already have a standing deal with two of our local aquatic stores for $/(trade) and wonder what the counts could be or should be. I have bought a new female albino that should be ready to start laying eggs b4 long she is <2" and growing really fast. Eventually may consider another male. There are two caves in the tank on opposite sides so should be okay. They are about 4" apart. We feel really good about where we are but wonder were we could be. More babies mean more excitement and fun for us but also means more free food…lol any suggestions?
    Thanks again and best of luck to you all!

    • says

      There’s no question that you’re losing fry to other fish. You will always have better results with a dedicated breeding tank. Not only will you be able to monitor the water quality much closer, but you can also ensure that no fry are picked off by hungry fish. With that being said, the minimum size for a bn pleco tank is really 20g, with larger being better.

      However, you will end up with a lot more fry in that situation, so you may want to consider how many you can sell before you start to breed them regularly. I know I’ve run into the problem of having too many fry to sell in the past. I hope this helps.

  13. Kenny McEwen says

    Oh… I forgot to add I have Ehiem 600s on the bigger tanks and a Ehiem 2213 (250) for the 16 so filtration is definitely not a problem.

    • Brendon says

      filtration doesn’t do anything for the bioload. if you keep them in the 16gal you will NEED to do very frequent water changes regardless of your filter size and flow rate. your filter doesn’t remove nitrates, water changes do.

  14. Atti Cole Samson says

    Hi Matthew, thank you for your informative article. It has me thinking that you may have hit on a possible reason for why we just recently lost our BN…we had him for two years and he was growing well and steadily. About two weeks ago we noticed his stomach had become enlarged and shortly after found him dead :( is it possible that he was…constipated? You mention fiber is important in his diet particularly if not fed a lot of vegetables and that a piece of driftwood would help. We did not realize this for the entire two years! Could he have survived despite and eventually succumbed to two years without adequate fiber?? Any advice would be greatly appreciated. I miss him, he was my favorite in the tank.

    • says

      It’s tough to tell. In many cases what you describe can signify constipation in plecos, but it can also be a sign of serious illness. Do you know if he was still pooping and what colour it was? Were any other fish sick in the tank? Many plecos can survive long periods without proper fiber in their diet, but they won’t be at their optimal health. If you do replace your pleco, just make sure to add driftwood to the tank, and feed it a steady supply of blanched vegetables. With that being said, I wouldn’t replace it until you can be sure there is no illness in your tank.

  15. jenkate94 says

    Hi, my male bristlenose is about 12cm and female about 10cm. When buying some D caves for them to breed in the shopkeeper suggested the smaller caves which are only about 10cm long, I bought the smaller caves but now have doubts about their size.. in your experience will this cave size be big enough or do you think it will require the larger caves (15cm) for successful breeding

    • says

      I’ve had success in flowerpots on their sides which were a similar size. Of course the bristlenose plecos were quite small then, but they will make do will small caves if need be. In fact, based solely on my experience, it seems that most plecos prefer smaller caves. I don’t know if they feel more secure, or they are simply easier to defend, but if given a choice, my plecos usually choose the smaller of the available caves.

      • jenkate94 says

        Well of course just after I ask the question my fish answer it for me anyway! I woke this morning to find the male in the cave and female sitting very close to it as well, hopefully this will mean spawning soon!
        Thanks for your help

  16. Jana says

    I have a pair of plecos and they breed every 6 weeks. I wanted to ask you what can I do to make them grow faster (if that’s even possible) so I can give them to someone or to a shop. I’ve got 400 already and just today another 100 have hatch. I tried to breed them in the beginning, now I can’t stop them :-) I do not want to split them, it’s nature, I’ll deal with it instead.. Thanks.

    • says

      There’s not much you can do to speed the process along unfortunately. You can just do what is already recommended – feed the fry small amounts several times a day. Make sure to keep the water as clean as possible, and give them a spacious grow out tank. These three things will ensure that they grow as quickly as possible, but still won’t make them grow very fast. This is why it’s so difficult to make money breeding fish – it takes so long to get them to the size where stores will buy them (that and it’s hard to compete with the giant fish farms these days).

  17. Emily says

    My pleco is not swimming well and looks like he is trying regurgitate something!! When I scooped him up to isolate him he was quite stiff?? What do I do??

    • says

      I would start with feeding it some peas. To prepare the peas, you should boil them for a few minutes, allow them to cool, and the squeeze the pea out of its shell. If it’s a problem with its digestion, then the pea should clear it up quickly.

      If it’s more seriously, you should consider medicating your bristlenose pleco. Does it poop still look normal? Or has it turned a whitish colour? Is it bloated at all?

  18. julie says

    What colour is there poop,he was in with neons and harlequins,looked so healthy has driftwood and bridges and all things they like ,they cost a bit to bye in nz so am not sure to try again? Would they live in bowl with no filter ?

    • says

      How big was the tank that he was in? What were you feeding the pleco, and how often? Did he show any signs of illness, such as a bloated stomach before he died?

      And they wouldn’t survive more than a few days in a bowl. Plecos produce a lot, and I mean a lot of waste. They would poison the water almost immediately, and either jump out to its death, or quickly die in the waste filled water.

      • julie says

        Hi and thxs for a reply ,i did a water sample at pet shop yesterday and she did a extra test and found my water had lost its hardnest so have to keep small bag of oryster shell in back of filter,we live in the country and have rain water that goes trough 2 filters and a ultra violet light to make it pure for us to drink.The tank is a aqua one tank eco style 47.I will test again next week and if all ok may try another one as looks like that was my problem .Fingers crossed .I feed him nutrafin max one a day.His body was perfect no bloating at all.

        • says

          It’s tough when you start messing around with the pH and hardness of the water. You need to take into account both the KH and the GH. I would recommend looking at buffering product, and you should pick up liquid tests to measure both the GH and KH. That will help you stabilize the water, but it also carries enormous risk that you can throw the whole aquarium out of whack.

          Another thing adding to the complexity, is that driftwood lowers the pH after a while, so you also have that working against you. Is there no natural well water or anything like that that you can use? Rain water and distilled water are both very difficult to work with in aquariums, and require constant testing and balancing.

  19. Mooney says

    Matt I have a well established 60 gallon tank. I have a run of the mill pleco and an albino bushy nose and had no real intention on breading. I was going to do a little rearranging and found a bunch of eggs being protected by the bushy nose. I looked on line to see if this is even possible but can’t find an answer. If it’s rare I certainly don’t want to lose any. I have mollies, guppies a bumble cat, a large albino rainbow shark and a reeves turtle. I do have three other tanks including a ghost shrimp and snail tank for feeding purposes. What should I do? Thank you for any information you can give.

    • says

      That’s an interesting situation that you have. It’s not unheard of for a female to lay eggs, but only males will guard the eggs. Are you sure your regular pleco isn’t actually a female bristlenose pleco? They can look very similar to common plecos, since they have very small bristles. If there is only one bushynose pleco in the tank, then the eggs will even go moldy and rot. Without a male they won’t be cared for, or fertilized.

      If you think there’s a chance that they could viable eggs, I would just leave them in the tank. If you want to breed them in a seperate tank, I would recommend moving the parents to a tank where they can breed. It’s a little complicated moving eggs, and you’ll likely have to treat them with a anti-fungal if the male isn’t there to care for them, and the tanks you mentioned likely wouldn’t be fully cycled for the load that fish fry would put on the tank.

  20. Mooney says

    It’s a male and female no question! Around 50 hatched some time last night. The female has no visible bristles and when I bought her she was in with a bunch of regular run of the mills completely separate from the bushy nose tank and cost next to nothing unlike the albino. If she is a black bushy nose with an albino father what can I expect from the babies? I’ve read that black is the dominant color in fish. Is this true? Also I’ve read that they can live in low to moderate salt. I have 5th tank that’s kept around .024… a soft coral, mushroom reef tank with a sailfin mollie, three chromis and a black and white clownfish. In your opinion what is moderate and is this true, can they actually thrive in saltwater? If by chance she is not a bushy nose, do I have something special and what should I expect or do I have something no one will want? Colors, size, pricing, rarity…lots of questions. Thank you for answering back. Your time, input and advice is much appreciated as I’m some what new to the hobby and can always learn more!

    • says

      Black does tend to be the dominant colour, but you should still see some albinos in there. In my experience you should see about 25% albino, and the rest should be the natural colour. Of course that can fluctuate wildly, and I’ve had natural colour give birth to albinos, so a lot depends on their lineage.

      As for the the salt, the numbers you provided sound like they’re slightly less than even brackish water. I’m no expert in salt water, but I’m pretty sure that coral can’t live in the numbers you provided – assuming they’re ppt (a normal salt water tank is kept at 1.025 ppt). And you definitely want to keep your bristlenose plecos in a low salt tank. Their habitat is is nearly salt free, unlike mollies which can live in both salt-water and freshwater tanks.

      And I can almost guarantee that you have a bn pleco female. Common plecos almost never breed in captivity, and it would be far too small to breed right now.

  21. Mooney says

    I should have been more exact when asking for technical support. You are very correct, .024 would not support a reef tank. I have mine at 1.024 and it has done very well. But I now know what is a low salinity level. I’ve been in the hobby for less than a year. I had some issues due to a lack of knowledge and new tank syndrome in the beginning. By reading books and help from people like yourself has taken me a long way. How long have you been in the hobby and do you have knowledge in all things freshwater? If so I may have other questions in the future. Thanks again for your help I truly appreciate it.

    • says

      That makes more sense then. lol

      And feel free to ask questions about freshwater stuff anytime that you have them. I’ve kept and breed just about everything at one point or another, so I should be able to answer most of your questions.

      • Anne says

        Just about everything? I wonder, would a molly be a good comapnion for my bristlenose pleco? I understand from reading up that they have the same diet -is that right? But are their other needs similar too? It would be nice to have a fish that swims differently in the tank, bring a bit more life… Pleco is now 7cm and has six bristles only all on the line of the upper lip, nothing further up toward the forehead, I think it’s safe to assume female? :)

  22. Mooney says

    It’s been my experience with mollies that they are a great addition to the tank. If you have a large tank and love LOTS and LOTS of babies. They can give live birth about every 30 something days. It will make you pull your hair out just trying to think of what to do with them all. Also they are little waste factories and require regular water changes. If you get one or three female sailfins depending on tank size you will be very happy and not have baby drama. You will see a obvious pecking order but it’s fine its part of life. They also have very similar needs of the pleco , so buy up and enjoy!

  23. LisaJ says

    The beginning of this week I noticed my first fry. Only 4-6. Thinking I sucked up the rest during water changes over past few weeks note aware. Yesterday found new batch of eggs! Two questions-

  24. LisaJ says

    Sorry my screen took off-Dad is fanning very well and I fully expect this clutch to hatch although some of them, about 1/2 have been eaten by something. Three questions-I am feeding peas-cooked/deshelled, zuchinni, and daphnia in addition to wafers, flakes, bloodworm variety. is this enough for fry? How do I keep water parameters pristine? I realize I can do water exchange with panty hose over tube (I wont get debri but will at least refresh water) but an earlier post indicated any change in water can be deadly. Do I only do 10% at a time every day? Last question-I am using PVC pipe 6″ for caves, the batchof eggs is just outside cave edge. These are my standard BN in my 29G. My albino BN laid a clutch at the same place in my Discus tank. Is it the thinkness of the PVC pipe or are the caves not long enough?

    • says

      Congratulations on getting your bristlenose plecos to spawn. The food that you’re providing them should be enough for the fry, though I would recommend cutting up the zucchini medallions and spacing them around the aquarium so they are easier to find. As for the water change, when I’m changing water in a fry tank I usually only suction near the top. Some waste will build while they’re tiny, but regular water changes will help this. And as long as you’re only doing around 10-15% per change you should be fine. If memory serves me, the other comment referred to introducing them into a whole new aquarium, which can be quite a shock.

      As for the caves, they should be fine. Although in my experience they tend to prefer smaller caves to lay their eggs in. I often use 3 inch clays pots buried in the substrae on their side. I’ve have very good success with that in the past, though I don’t see how larger would be a problem. As long as they’re laying the eggs, you should be good.

  25. CJ says

    Question. We just purchased a Bristlenose 4 days ago. The first day he was in a few different spots but not eating. For the past 3 days he has Ben on one of our cave rocks in the center of the tank and has not moved from what we can tell. I dropped a couple of alge waffers in and he was not interested at all. We have a large peice of driftwood in the tank and it has collected a significant amount of “fuzzy stuff” that we thought he’d go nuts for, but he has only touched it for a split second when we first put him in.
    The second day I noticed a bunch of white spots on him that looked like ich to me. It’s hard to tell because he’s a white albino but the spots on his fins don’t seem to be real organized with their placement. I called the pet store and they said that ich was highly unlikely because they are not real prone to getting ich. However, we started to treat it Paragaurd anyway. We currently have 2 mollies in there that survived the cycling and they don’t have any white spots. All water levels and temp is as they should be too. Please help. What should we do? Or are we just paranoid?

    • says

      Are you able to send me some pictures of the bristlenose pleco to me?

      Otherwise, you need to be really careful with ich treatment in catfish. Since they don’t have any scales, they are very sensitive to any chemicals, and it should only be used at half strength with any catfish. You should also turn up the temp very slowly to about 86F for about a week. Make sure it is very slowly over the course of several hours or days. Combine this with daily small water changers, making sure to thoroughly suctions the bottom of the aquarium, and you should be able to treat the ich (assuming it is ich).

      Salt is also handy in treating ich, but since you’ve already used the chemicals and you also have to be careful with catfish, I don’t know if it would be worth the trouble now.

      The paraguard may also kill off some of the beneficial bacteria in the tank, so keep an eye on your ammonia levels. Though the small daily water changes should help keep that under control. I hope this helps.

      Also, did you remove the carbon insert from your filter before adding the chemicals? If you didn’t, your filter may have removed all of the chemicals very quickly.

      • Cj says

        Thank you, I will try and send you a picture sometime today. He is REALLY white and is in a position that may be hard for you to tell. On top of that, we had added a little peat a while back to bring the PH down. So the water is a little yellow. The only thing we have done is the Paragaurd. No salt because I have heard that it can be very harmful to plecos. We also do not use carbon, we use media in the filter. Day 5 and he still hasn’t moved or eaten. I was thinking of trying to throw some zucchini in there to see if he latches to that but wasn’t sure if I should force anything. The 2 molly fish seem to be fine, still ornery and no white spots. We haven’t done any water changes since we got him. When you say small daily water changes do you mean 10%, 20%, 30%? We were using spring water which was why we battled with PH levels but we just picked up some OI water from the fish store (fingers crossed that is a good thing). Sorry to be so inquisitive but we struggled with all levels of the water while trying o get it cycled and have been down to a 7.6 PH with 0 ammonia. Nitrates and Nitrites for about 2 weeks now. Super excited about our BN and don’t’ want to lose him. Should we stop with the Paragaurd or continue? We really don’t want to use salt… it was a disaster with the last out break of ich a few months ago when cycling.

        • CJ says

          Hey Matthew update on our BN Mr. Stash. I did email you some pics on Wednesday. But yesterday he moved around a bit, checked out a few more resting spots and even checked out the fuzzy driftwood for about 30 secs. He is still not interested in the zucchini (tried it again) but his whites spots are no longer there. We stopped the Paragaurd on Wednesday after you had said it could effect ammonia but we did keep the temp up to 85. Maybe it was just a matter of him getting comfortable.. we will see. However, today was sad morning, my Dalmatian Molly past away last night. Not sure what happened because he was eating, picking on the other molly as always and didn’t seem sick at all. It’s a bummer too because he and the other molly were the only 2 to survive the cycling of this tank and even an outbreak of ich we had 4 months ago.

  26. Robert says

    Hi there, I left a message in October asking how old they’d have to be to order to breed. Thank you for your advise however I do have another question for you now. 5 days ago I noticed fry emerging from a cave in my tank and so far I’ve managed to count at least 9 fry (3 albinos). With the fry I have 4 adults, 2 male and 2 female. In the last few weeks I’ve noticed the males becoming very aggressive towards each other. I have a second tank with only a few loaches and 3 barbs in it, should I move one of the males to that tank to calm things down?

    • says

      How large is your tank? Generally speaking, as males grow older, they grow more aggressive to both males and females. Though the aggression towards females generally doesn’t escalate until it becomes a problem.

      If you tank is under 55 gallons, I would recommend removing one of the males. Also, what kind of loaches do you have? Most loaches are compatible with bristle nose plecos, though I have heard of rare issues with dojo loaches in the past.

      • Robert says

        Yeah my tank they’re currently in is about 35 UK gallons so looks like I’ll have to move some to the other tank. The loaches in the other tank are 3 khuli loaches. They seem to be quite unsocial in never coming out of their beloved little bush.

        • says

          You’d be hard pressed to find any fish that really bother kuhli loaches. They’re great little fish, but it takes a lot to actually train them to even come out for feedings. I my opinion, a bristlenose pleco would be fine with them.

  27. says


    I have a female bristlenose, about 4 years old now. We refer to her as a bit of a tank as she barges her way everywhere and was one of only a few of our tank mates to survive a bad outbreak of ich a few years back.

    Over the years she has gotten a mottling look on her scales, so she isn’t all black any more, she has tan patches. I thought this may be due to her bashing past the wood in the tank and generally charging around across the gravel like she is indestructible. Are tan patches normal?


    • says

      They are normal, so you don’t need to worry about them. The colouration of bristlenose plecos change as they age, and mine developed similar patches as they grew larger. The only time you need to be concerned is if she starts to loss her colouration.

  28. Emma says

    Hello I could really do with some advice. My boyfriend has 2 bn plecos, 10 months old and early January they had 12 babies. I’ve recently started my own tank and after a couple of weeks of it being set up, I tested the water and everything and the levels were good so I had 2 of the baby bn plecos from my boyfriends tank. At this point they were about 2cm long. They were living in my tank for 4 weeks however tonight I found one had died. I feel so sad. For the last two week my tank tank seemed to be building up a lot of slime and algae on the plants and ornaments and sides of the tank. I have to clean the filter out every couple of days cause it gets full of slime! I hadn’t been giving them algae wafers or anything as the tank was building up so much algae anyway. Twice in the last 3 weeks I have done a 30% water change to help combat the slime build up. I don’t know what to do now. I’m scared of losing my other bn pleco :( any help and advice would be greatly appreciated. Thank you.

    • says

      I’m sorry to hear about you losing your bristlenose pleco. First things first – how large is the tank that you’re keeping them in? Also, are they alone in the tank?

      As for the algae, I wouldn’t be too concerned about it. It usually means one of two things – too much light, or too many nutrients. While it is unsightly, it doesn’t harm the fish at all. If the problems are as severe as you say, it’s likely either your water, or you have the tank in direct sunlight. If it’s in sunlight, you can simply reposition the tank.

      And while plecos do eat algae, it’s a good idea to supplement their diet with regular food. Also, is there any driftwood in the aquarium? It’s important to bristlenose plecos health.

      Was there anything wrong with your pleco prior to its death? Bloated stomach? Light patches? Any fuzz? Let me know, and hopefully I can pinpoint the problem. For now though, definitely start feeding your remaining pleco again.

      • Emma says

        Thanks for getting back to me. It’s a 19 litre tank and i only had the two baby plecos in there. I didn’t want to put any other fish in until they were a little bit bigger. The tank isn’t in direct sunlight but it is open top so not sure if that’s got something to do with the slime build up? Also the filter is at the top of the tank so maybe it’s not doing a very good job. The tank is a fluval chi tank, it’s probably best you Google it to see what I’m talking about. There appeared to be nothing wrong before he died. Id saw him thr day before and he was moving around just fine, that’s why I was quite shocked when I saw he had died. I need to concentrate now on ensuring i do the best for my remaining pleco. I’ve not got any driftwood in there so I’m definitely going to get some asap and i will start feeding my remaining pleco broken up algae wafers and hopefully he should be ok. Thanks for your advice :)

        • says

          It’s strange you’re getting that level of slime with no direct sunlight. Until you get it under control, I would also reduce the amount of time that the lights are on in the tank to a maximum of about 8 hours a days. My bet would be that you have a high phosphates in your water. You may want to consider a phosphate control product from your local fish store.

          Beyond that, I can only wish you luck. I hope that your pleco makes it, but it sounds like you’re doing the right things to keep it healthy.

  29. Crouchy says

    Hi Matthew,

    Love everything I have been reading. Ive had a 4ft tank for a while now and my Bristlenose Pleco has just had babies. My other Cichlids started racing around the tank so thats how I found out haha. I also found that my Cichlids have had babies but I have only managed to find 4 of them.

    I’ve pulled all the babies I can out of the tank (in water from the tank). I was just wondering if I should put them all into a new tank (with the clay tube they hatched from in) or leave them in there or put them in a small breeding cage on the side of the tank.

    Would really appreciate if you had the chance to reply!

    Thanks a lot in advance! Cheers Ben.

    • says

      Hello Ben,

      It’s a tough decision – unless you have a fully cycled tank to put them in. On the one hand I’m not a big fan of the breeding cages, since a lot of detritus tends to build up in them, and they don’t always work that well. Depending on the make, some fry can get stuck in them, and I’ve had high mortality the few times that I’ve used them. They seem to work fine for very small numbers of fry, but anything more than a handful quickly become a problem.

      On the other hand, unless you have a fully cycled tank, you may not have a very good survival rate in a new tank. Bristlenose pleco fry are very sensitive to water conditions, and if a tank isn’t cycled, you’re going to lose most of them in my experience.

      However, there are ways around cycling a tank. The first and most effective way, is to heavily plant the tank with fast growing plants that will use up most of the waste produced by the fish. I recommend hornwort especially for this, though others like anacharis and cabomba also work well. In addition to this, I would recommend small, daily water changes of about 5-10% a day.

      With all that being said, probably your best bet is the breeder box right now, though if you become interested in breeding them in the future, I would definitely recommend a dedicated nursery tank. I hope this helps.

  30. Jozef sanders says

    Hi I got a new tank which is 125l and set it up 4 days ago and I have some questions
    First how long will it take for the pleco to get to breeding size.
    Second thing is how do I prepare the zucchini


    • says

      Sorry for the delay in getting back to you. Bristlenose plecos generally start to breed when they’re around 3 inches in length. It’s hard to pin down an exact age, since so much can influence how quickly they grow. That being said, they should normally be breeding at around one year in age, though they can sometimes breed before that.

      As for the zucchini, just scrub it under cold water, then slice it into medallions. After you have sliced it up, you should boil it for a minute or two just to blanch it. Then it can be feed to your fish.

  31. Alicia says

    I have just purchased two BN Pecos and I believe my male isn’t acting right. He won’t stay stuck to the wall, he will get on the side of the aquarium for like 15 seconds lunge backwards then back to the wall… It doesn’t seem as though he is getting good suction. When the lady at the store went to put him in a bag for me he got stuck in the net and took about 10 min. To get him off of it. She had to cut the net then work if off his “spikes”.
    He engaged them in fear but she did get him released after a while. Now I am not sure if he is just traumatized and will soon come to. But I just don’t know what to do or how I can help.

    • says

      It sounds like he may have been slightly injured, but I can’t pinpoint anything specifically beyond that. The best thing that I can recommend is too keep the water clean, keep your pleco well fed and keep an eye on your bristlenose pleco. If anything changes though, take a picture and send it my way. Hopefully I’ll be able to diagnosis any problems then.

  32. Ashley says

    I’ve recently notice for the past few days that my briselnose has been digging a cave under our skull and has been guarding it from the other fish we have in the tank (ghost knives, pictus and platys). If the female has laid her eggs and the male is guarding them what should I do when the fry hatch?
    We have only ever had one set of babies from our platys which were eaten. Should I try to catch them with a net or something and put them in a breeding box?
    Thank you in advance :)

    • says

      It can be difficult to notice when the bristlenose fry are born, and catching fry with nets can sometimes injure them. I would recommend using a small cup if you’re planning to catch them, which often isn’t that hard because they’re not that mobile when they’re young.

      A breeding box is probably the best option in this situation. Normally I would recommend having a dedicated tank for them, but there’s no way that you could set up and cycle a tank before the fry are born. Once they are put in a breeding box, make sure that you keep it very clean, and always keep an eye out for any fry that may have become tangled in it. Also, remove any food that isn’t eaten in the breeding box after 24 hours, since it it will start to foul your tank.

      I hope this helps.

  33. Vanessa says

    Hi Matthew,
    Thanks for the article – it’s very well written and enjoyable to read.

    I’m setting up a new tank, it’s currently cycling and growing plants. I have 3 young bristlenoses – at this stage they’re too small to tell what gender they are, but I’m hoping once in the new tank they’ll grow well, and I can then move them around between my other tank (and friend’s tanks) to have just a male and a female BN in there. (From different sources of course, to avoid mating siblings.) The purpose of this new tank of mine is not only going to be breeding BN, but I’ve made a tereracotta cave and I’m hoping maybe in a year or two for BN breeding to be a possibility.

    My question is about what other fish you think I can keep with them. My first tank has only a betta with the 3 little BNs (2 – 4cm). He and the BNs leave each other alone nicely, but I know bettas are meat-eaters who will happily snack on baby BN fry.

    Ideally in my new tank I’d love to have clown loaches, but I’ve heard they will eat BN fry. How about a school of neon tetras? And/or glass catfish, would they be a good match? Are there any gentle species of fish you know of that will happily live alongside breeding BN without snacking on the fry? I know it’ll be a year at least before I have any BN fry to worry about, but I’m reluctant to add fish to my tank if I’m only going to have to re-house them down the track.

    Cheers, Vanessa
    (Melbourne, Australia)

    • says

      Hello Vanessa,

      Unfortunately most fish will eat anything that they can fit into their mouths, and few fish aren’t able to fit fry into their mouth. There are a few possible options for bristlenose plecos tanks though. I have found that the number of fry casualties are lower in a tank with corydoras catfish, though it doesn’t make for a very exciting tank with all bottom dwellers. However, they do love eggs, so if the bristlenoe male slacks off, you’re going to lose most of the eggs to them.

      If you don’t mind losing a large number of the fry, then your next best bet would probably be smaller fish. Like you mentioned, neons would probably be a good choice, and guppies or white cloud mountain minnows might also work. These fish seem to have less of a hunting instinct than most other fish, and if you keep large amount of live plants and other hiding places in your tank, you may have a handful of fry reach maturity. Definitely stay away from tetras, danios and most other minnows though.

      But the only real way to go if you want to breed them, is a bristlenose pleco tank only. If you decide to go with other fish in the tank, let me know how it goes.

      • Vanessa says

        Thanks for that Matthew,
        Yes, I had suspected that most fish would probably nibble on the fry if given a chance. I think my plan will be to go about everything as normal and get some smaller fish in, until I have bristlenoses that look interested in breeding, when I’ll move the other fish out of the tank. Might be a good excuse to set up a third aquarium… *grins*. Thanks for your advice!

        • Robert says

          Hey there, I’m not a pro like Matthew but I’ve got plecos breeding comfortably and the fry not being harmed at all in a community tank with Neon tetras, Guppies and even Danios. Rob

          • says

            Hello Robert,

            I’m curious how large your tank is, and what kind of danios do you have? I’ve rarely had any fry survive in a tank with any of the more common danios in it. I find zebra danios are especially voracious eaters. Do you have any kind of special setup, or is it all just happening naturally?

      • Vanessa says

        Hi Rob, that’s very interesting, thanks! Maybe I’ll try with tiny fish too, and see what happens. Cheers!

  34. faith says

    Is there a specific way to tell if they are male or female? I have an albino bristlenose and I’m not sure if it’s a male or female.

  35. Alex says

    Unaware that the 3 BNP’s i put in my tank would breed, i had quite surprise when i cleaned out one of the two canister filters i have on my 175 gallon tank. i took it to the tub in my spare bathroom emptied it and started cleaning the components, that’s when i noticed 8 baby fish swimming around my tub! not sure how many I lost to the drain but a managed to save the 8 and get them back in the tank. They were thriving inside my filter! since then i take cleaning a little more carefully and i have noticed more smaller fish also coming out meaning that they are breeding continuously. weird thing is that the breeders are still really small (2″) and have yet to develop significant bristles. Ever run into breeders that are not adults yet?

    BTW, great page, lots of good info.


    • says

      I’m glad you enjoy the page. Bristlenose plecos can breed relatively young, though I’m never had them breed that small before. Usually mine are almost three inches in length before they start breeding. You must be doing something right. And I used to always discover baby bristlenose plecos in my filter. I eventually switched to a sponge filter, since I was worried about how many I might be losing to the propellers of the hang on back filter.

  36. laura says

    Hi there,

    Was wondering if you know anything about dominant genes in BN plecs? I have 2 BN’s that I purchased a month ago. We now have at least 23 fry in our 79 gallon tank, however both our BNs are dark, yet 70% of the fry seem to be albino. Just wondering whether albino tends to come out as a dominant color?

    They have all stayed in our community tank, and much to my surprise, none of the catfish or swordtails seem to have gained interest in them, so I am hopeful we will get a good few to sell from this batch.

    Thanks :-)

    • says

      Many of the fish you purchase at the fish store are related, and both of the fish you bought likely had the recessive albino gene. It’s quite rare to have that many albino fry from two parents with natural colouration, but it can happen. It’s like the bristlenose plecos in that tank were normal coloured fish from albino parents.

      You actually see this quite a lot, and I’ve had convicts, corys and bristlenose plecos that appear normal, only to have large quantities of albino fry. At some point they must have been rejects from attempts to breed albinos, and when I’ve breed albino plecos in the past, you usually end up with a normal looking bn plecos.

      And bn plecos always sell really well. I sold them for years before the big local chains started selling them (it’s hard to compete with stores that sell them for one dollar on sale).

  37. Kate says

    Hey Matthew! My 2ft tank has two goldfish (starter fish who lived), a jack Dempsey (rescue) and two bn plecos, we recently discovered the male guarding eggs in one of the caves, would you recommend moving both BNs with the cave into a breeding tank so the fry will not become food for the jack Dempsey? What size would this have to be?
    I read above the water is very important so if we took water from the original tank and made this breeding tank would this be the best way to set it up.
    Any help would be appreciated as my parents are excited to be grandparents! 😉
    Thanks, Kate.

    • says

      Hello Kate,

      It’s always easier to raise bristlenose pleco fry in their own tank, but unfortunately it takes a few weeks to setup a tank for them to live in. The problem is that a new tank has to be cycled. It can take weeks for the beneficial bacteria to build to process the fish’s waste. And if you put any fish into an uncycled tank, they’re most likely go to die. And this is even more true for fry, who are extremely sensitive to poor water conditions. You may want to do this in the future, but probably the best course of action is to just hope they survive in the tank for now.

  38. mike says

    Babies are easy to move to another tank if you have them spawn in a cave. A few days after they hatch, when yolk sac is getting small, just remove the whole cave dad and all. Once he lets them out, just net him and remove the cave.

  39. says

    Hello Matthew!
    I have a 240l community tank, I want to add a Pleco to control my Algae, especially the brown one. I just want to know if the Bristlenose Pleco is a dirty fish, I read that si one of the dirtest. Thanks.

    I have Angel Fish, Corydora, Dojo

    • says

      They really are a dirty fish, but as long as you don’t overstock your tank they should be fine. Just keep on top of the water changes and they won’t overly affect your tank. Though it is true that is seems plecos only live to eat and poop, and then poop some more. They’re in close to the same league as goldfish for a messy fish.

  40. says

    I have a 160 L tank, which is kept at 70F, two filters, a Fluval 4, and an Eheim, and about only 1cm. of gravel – no plants, because the plecos ate them instead of the algae, and I change 30L of the water every seven days. In the tank I have three fancy goldfish, each 10 cms body length, one adult male BN pleco and an adult female. All have been together in the tank for two years now, and (I cross my fingers when I say this) all the goldfish and the female BN are healthy – I never get to see the male – but presume he must be okay as they bred a couple of months ago. I have to be honest and say that my only interest in the plecos is as algae eaters, and supplement their diet with a few sinking spirulina flakes a couple of times a week. However, they don’t do a very good job at all of cleaning the algae off the glass, nor are they at all interested in any of the suggested veggies, although they do scrape away at the bogwood I provided for them. At this point I’m wondering if they are actually getting their fill by feeding on all the soft, sinking goldfish pellets that end up in places where the goldfish can’t get at them, such as in their separate ‘caves’. Is that possible, and is that sufficient for them, long term, as I naturally want to treat them properly? Thank you.

    • says

      They will eat any of the missed the goldfish food, but it’s also important to provide them with their own herbivore food. But depending on the goldfish pellets you’re offering them, they may already be getting exactly what they need from them since goldfish are also mainly herbivores. One of the issues you may be having is that the water may be too cold for them. Goldfish are a cold water fish, and bristlenose plecos are a tropical fish. They may be sluggish and hiding if the water is too cold for them. In the future, it would be best to give them separate tanks with their own preferred temperatures in them.

      As for the algae, bristlenose plecos only help with the maintenance, and they will never keep a tank clear of algae on their own. If you want a really effective algae eater, I would pick up some Malaysian trumpet snails. Though many people don’t like the look of snails in their tank, so they’re not for everyone.

      I hope this helps.

  41. says

    Thank you for your help, Matthew. I have obviously been expecting too much of my plecos by way of scavenging the algae, so it’s good to know that there is nothing wrong with them from that point of view. Oddly enough, right after posting my question to you, and saying I’d not seen him, both he and the female appeared at the entrance to his ‘cave’, and since then he’s been darting out quite aggressively if either the female or any of the goldfish poke their noses into his lair, which makes me think that perhaps they’ve mated again. I’m pleased to say he did look very healthy and robust. I’d thought of snails, but had read somewhere that goldfish have a tendency to bite off their eyes… Unfortunately, I don’t have room for any more tanks, so think I’ll take on board your comment re the temperature for the time being, and raise it a couple of degrees to 72F to see if that livens them up a bit — the goldfish won’t mind. Re the goldfish food, I use the New Era sinking goldfish pellets, which are soft and keep the digestive systems of my deep-bodied fish in fine shape. Thanks again.

    • says

      Some species of fish prey on the larger snail eyes, but that really only applies to apple snails. The snails I mentioned are quite small, and burrow into the substrate during the day. Still, they can be slightly unsightly at times, so they’re not for everyone.

      And I’m glad I could help.

  42. Carly says

    Hello, I have a quick question – I have not been able to find info with confidence online. I have 3 x 3.5cm bristlenose and have been feeding then 2 zucchini slices about 5mm thick and 1 algae disc each week. The also have plenty of wood in the tank, plants and places to hide. My question is am I feeding them enough? They just seem to keep eating and i have been told if i over feed the fish they will die. Or is it not enough? I have found plenty of info on what to feed just nothing on how often. I am amateur at this and your help would be much appreciated!

    • says

      I would definitely feed them more than that. While a fish can go several days between feedings, it is optimal to feed them everyday. I would give an algae disc every day, and give the zucchini as a treat now and then. Make sure to remove any uneaten zucchini after 24 hours or it will foul the water.

      And the main concern with overfeeding is that you will foul the water. Any uneaten food breaks down and affects the water quality. As long as your fish are finishing off the wafers and the uneaten vegetables are removed, you should be fine. Make sure to keep up with your water changes though.

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