Common Pleco Stats
Minimum Tank Size: 55 Gallons (75 Gallons Recommended)
Care Level: Easy
Water Conditions: 6.5-7.5 Soft to Medium
Temperature: 72-86 F (23-30 C)
Maximum Size: 24 inches (60 cm)
The common pleco (Hypostomus plecostomus), also known as the sucker fish, is a staple of the aquarium hobby, and is easily one of the most popular fish available. They are found throughout South America, and have in recent years been reported as an invasive species in several countries, most notably in the several southern United States.
Their natural habitat consists of streams and rivers and they are also found in shallow, low oxygen ponds during the dry season. They tend to prefer slow moving water with sunken driftwood and plants that provide shelter during day. The reason that they shelter for much of the day is that they are nocturnal and are rarely active during daylight hours – a behavior that you can expect in the home aquarium. While many will become more active during the day after being kept in captivity for several months, they should always be provided with adequate hiding places such as caves, rock over-hangs or large pieces of driftwood.
Many of the plecos for sale in pet stores are juveniles, and don’t be fooled into thinking that they are a small fish. While most are sold in the neighborhood of only one to two inches, they quickly grow to aquarium busting sizes. It’s not unusual for a pleco kept in proper conditions to reach over 24 inches (60cm) in length – a size that will overwhelm most aquariums.
If you are looking to pick up a male and female pleco for breeding purposes, then you are about to be disappointed. They are incredibly difficult to sex, and while many people claim to have a system that can easily sex them based on their size, or the shape of their fins, it’s nearly impossible for the average person to determine their sex.
Because common plecos can grow to such massive sizes in the home aquarium, only the very largest of aquariums can be used to house fully grown adults. They can be kept in smaller aquariums while they are juveniles, but should be moved to at least a 55 gallon aquarium as soon as possible. And even with a 55 gallon aquarium, they will often become too large to turn around in the tank, and should be provided with at least a 75 gallon aquarium, with 100 gallons being preferable.
Something else to keep in mind when choosing an aquarium for a common pleco, is that they are known to become extremely aggressive when they reach adulthood. While juveniles are generally an excellent community fish, any adult plecos should be kept in a semi-aggressive tank, and should never be kept with any other common plecos. They can occasionally be kept with other species of plecos, but this can be hit and miss at the best of times and should be avoided if you don’t want to risk a fish fatality.
Their large size, and equally large appetites should be considered when choosing a filter, and any fish tank containing a common pleco should be heavily over-filtered. It seems their one goal in life is to eat and poop, and they will put a strain on even the best filter. The best way to keep up with their enormous bio load is to use an HOB (hang on back) filter in conjunction with a large sponge filter.
I would strongly recommend choosing an Aquaclear Power Filter for a common 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.
However, if you have access to a larger budget, then common plecos are a prime candidate for canister filters. These are usually the best option, and will keep the water sparkling clean even in tank with a prolific poopers like common plecos.
Most people will tell you that the common pleco is a sucker fish, and can live off algae alone. Unfortunately, nothing could be further from the truth, and this belief leads to many underfed and malnourished plecos. They are actually omnivores, and eat plant material, algae, insects and small crustaceans in the wild.
This diet should be reproduced as closely as possible in the home aquarium, and they should ideally be fed algae wafers and a high quality flake food. They can also be fed frozen foods, with bloodworms being the best option since they sink, and are easy for plecos to catch. One of the best algae wafers to feed them is Hikari Algae Wafers and I use them for all of my plecos.
It is also important to regularly feed them a variety of fruits and vegetables. Their favorite foods are blanched zucchini medallions, shelled peas, cucumber and any soft melons. But you can always experiment and try different fruits and vegetables, and they will also greedily accept broccoli, lima beans and a wide array of other vegetables. With that being said, they should never be fed any acidic fruits or vegetables (oranges, grapefruit, tomatoes, etc.)
Common plecos require a large amount of fiber in their diet, and regularly feeding them vegetables helps them to obtain most of their required fiber. But to be sure that they are getting enough fiber in their diet, they should always have access to driftwood in their tank. They will constantly rasp on the driftwood, ingesting tiny pieces of wood which helps with their digestion. If they aren’t provided with driftwood, they can become seriously ill in a short period of time.
Breeding common plecos is incredibly difficult and only a small number of hobbyists have ever successfully bred them. If after reading that, you would still like to give breeding a shot, then the first thing that you need is a very large tank. Since adult common plecos are notoriously aggressive, the minimum size tank for breeding adult plecos is approximately 100 – 200 gallons.
The tank should contain as many hiding places as possible to reduce aggression, and a cave like hollow should be built into the tank. Some people report success with large clay pots on their side, but the truth is that it is hard to mimic the river bank caves that plecos breed in in the wild.
Once the male has chosen a “cave” to breed in, it will meticulously clean the sides and attempt to attract the female into the cave. If the female is enticed in by the male, it will deposit eggs on the side of the cave, and the male will then set about guarding the eggs until they hatch.
The eggs will generally hatch in few days, and the fry can be feed infusoria for the first few days, and then will accept most commercially available fry foods and baby brine shrimp. They will also accept spirulina powder, but too much of this can quickly foul the water.