There are few things more frustrating to a fishkeeper than dealing with algae. Even if you follow all the rules – no natural light, don’t overfeed your fish, and don’t overstock your aquarium – you’ll still often find yourself fighting algae blooms. And no one enjoys spending hours laboriously scraping algae off of aquarium glass and decorations.
But the good news is that you don’t have to handle the algae by yourself. There are several fish and invertebrates that you can enlist as a cleaning squad to keep your aquarium clean and free of algae.
If you want the best algae eater for your aquarium, look no further than bristlenose plecos. These fish consume large amounts of algae throughout their lifecycle (many so-called algae eaters only consume algae when they’re young), and they can be kept with nearly any species of peaceful or semi-aggressive fish. However, some juvenile bristlenose plecos may experience problems with larger cichlids, so place them with convicts and other semi-aggressive fish with caution.
And unlike their larger cousins, the common pleco, bristlenose plecos stay relatively small. If you provide them with a large enough aquarium, several of these catfish can be kept together, though it’s a good idea to keep more females than males. If too many males are kept together, they will battle with each other over caves and will try to consume any eggs their rivals have fertilized.
An often-overlooked algae eater, Amano shrimps are one of the best algae eaters you can add to an aquarium. These invertebrates constantly browse and will consume most types of algae – something most other algae eaters won’t do. If you keep a handful of Amano shrimp in an aquarium – especially if you add another algae eater like a bristlenose pleco – they will do virtually all the work of keeping an aquarium clear of algae.
The only downside to these shrimp is that they’re often viewed as prey by larger fish. That means they should only be kept in an aquarium with small, non-aggressive fish. Most fish suitable for a community tank should be fine with Amano shrimp.
The otocinclus catfish, also known as the oto cat, would probably be ranked as best algae eater on this list, if not for their one downside: The majority of the otocinclus for sale in the hobby are wild-caught. This makes them fragile and prone to disease. It’s not uncommon for otocinclus catfish to die shortly after being added to an aquarium, which turns off most fishkeepers from owning them.
But if you can find some healthy otocinclus catfish, they make an excellent addition to almost any aquarium. They continually consume algae and will make a surprising impact on a mature fish tank in a matter of days. But if you purchase these fish, it’s important to remember they need to be kept in groups of at least six.
Bonus: The Worst Algae Eater
Of all the fish being sold as algae eaters, the Chinese algae eater is by far the worst. In fact, there are some who argue they shouldn’t even be called algae eaters. While the young do consume some algae, it’s rarely in large enough quantities to make a noticeable difference in an aquarium.
And worse, as a Chinese algae eater ages, not only does it consume less algae, but it becomes large and aggressive. This makes them unsuitable for most community aquariums, and more than a few inexperienced fishkeepers have ended up with Chinese algae eaters terrorizing their fish tanks.
It’s best to stay away from these fish and instead choose Siamese algae eaters, which look similar, but are far more peaceful and better at controlling algae.
While all the invertebrates and fish on this list consume algae, it’s important to realize there isn’t enough algae in most aquariums to support them on algae alone. They should always be offered supplemental food, and herbivore fish foods are usually the best choice. I recommend choosing Hikari Algae Wafers, as it contains a good mix of vegetable matter and protein. Also, it’s a sinking food, which means it will reach the algae eaters dwelling on the bottom.