Top 7 Freshwater Aquarium Algae Eaters

Algae eaters can be a welcomed addition to any freshwater tank when it comes to reducing maintenance time. For larger tanks, most people opt for algae eating fish. For smaller community tanks, many shrimp & snail species are viable choices. Depending on the type of algae growing in your tank, you may want a different type of algae eater that really loves that type of algae.

It’s important to keep in mind that algae are not the only thing most algae eaters will eat. For instance, when it comes to plecos, they require real wood in your tank as a supplement to their diet. A lot of algae eaters tend to end up eating your fish food and in some cases develop taste buds only for fish food and no longer for algae!

You should also keep in mind the overall compatibility of the other fish in your aquarium. Some breeds of plecos and Chinese algae eaters, for instance, can get more aggressive as they age. Last but not least, make sure the water parameters of your algae eater matches that of your tank. On to the list!

Aquarium Algae Eaters for Freshwater Tanks

1. Plecostomus (pleco)

Quick Stats

  • Temperature: 23-28c ; 73-82F
  • PH:5.6-7
  • Size: 5inches++

One of the most common algae eaters on the market. When buying one, make sure to take note of the breed as many plecos grow to a very large size (common – 18inches, bristlenose – 5inches). If you have an immediate algae problem, go with a young/baby pleco and he will eat up your mess in no time. They tend to keep to themselves however just like humans they all different personalities.

For both size and behavior, I would avoid the common pleco and go with something like a bristlenose or even fancier. You will need real wood in the tank as well as potentially algae wafers as their top foods. Sinking things like cucumber chunks are also one of plecos favorite treats! Keep in mind that plecos are poop factories and will greatly affect your water conditions. If you have sensitive fish or are a bit lazy on the maintenance end you may want to think twice.

2. Otocinclus Catfish (Ottos)

Quick Stats

  • Temperature: 20-26c ; 68-79F
  • PH:6-8
  • Size: 1.5inches

The Otocinclus Catfish is a great small algae eating fish that does well in most tanks. Their adult size reaches only about 4cm which makes them versatile in many tank sizes than compared to plecos. Ottos are schooling fish so be prepared to buy them in a group of 4 – 6. Being bottom feeders, they will over time get used to eating the scraps left over from your fish food just so you are aware. Ottos eat specifically soft algae and also are great at eating algae off plants without harming the plants.

Being a smaller fish, you may have issues if housing them with more aggressive type cichlids, who if large enough may try to eat them.

3. Siamese Algae Eater

Siamese Alga Eater

Quick Stats

  • Temperature: 24-26c ; 75-79F
  • PH:5.5-8
  • Size: 6inches

The Siamese Algae Eater hails all the way from the regions of Thailand/Malaysia. It’s not uncommon for these guys to get mixed up with the otto and Chinese Algae Eaters. The best way to identify them is by their black stripe all the down the middle to make sure you’re buying the right fish.

It is a fairly hardy fish that prefers faster moving waters, so keep that in mind when incorporating with other tank mates. They tend to favor brush, thread, and red algae over other types so if you have one of those here’s your solution. SAE’s are quite suitable for community tanks and can be kept in groups, however, like most groups of fish a pecking order may be established leading to aggression.

They do best in water temperatures of around 25 C and require optimal water conditions to thrive well. Both ottos and SAE’s prefer to have places to hide, forage, and clean making them ideal for planted tanks. Please keep in mind that their final size can reach around 6 inches so plan accordingly.

4. Amano shrimp

Quick Stats

  • Temperature: 22-26c ; 72-79F
  • PH:7-7.5
  • Size: 1-2inches

One of the most popular shrimp species, the Amano shrimp are the ultimate aquarium nannies. Not only do they eat algae, but they clean up leftover food scraps and decaying plant matter. Although starting out quite small, they can reach an end size of around 2 inches in length which is still good for many smaller aquariums.

They are great to have in groups and it’s not uncommon for people to have shrimp only tanks. Some drawbacks are that these shrimp can become food for larger fish, so they definitely require very passive fish species if put into a community tank. Other people have succeeded in keeping them with fish by having heavily planted tanks giving the shrimp plenty of places to hide and reproduce on their own.

If you go the planted route keep in mind that if using any type of fertilizer, any copper residual found in it will be harmful to Amanos. The same can be said for medicating tanks, where almost all fish meds containing heavy metals that will kill your shrimp. If you need to treat a community tank with either fertilizers or meds, remove the shrimp first.

5. Ramshorn Snails

Quick Stats

  • Temperature: 24-26c ; 75-80F
  • PH:7-7.5
  • Size: Up to 1 inch

Well unless you’re really into snails (snail tank), I would steer away from this algae eater. Lots of people have bought Ramshorn snails to fix their algae problem, only to be left with a massive Ramshorn snail population taking over their tank. If this is already a problem for you, an easy remedy is to buy assassin snails (what a cool name!). They will make quick work of your snail population problem. If you ever buy plants, there’s a small chance there are Ramshorn snails sneaking on board.

If you’re still keen on getting these snails, they reach an average size of about 2cm. They have been known to munch on any vegetation you have going on in the tank but focus primarily on algae on all surfaces. If you are running a breeding tank (which should preferably only housing that one species), these snails may potentially eat the eggs.

Quite a few fish will eat snails, and if you want to go into some of the more unique species of fish I would leave these guys out of your choices. That being said, they make a lot of fun for smaller planted tanks if that’s the route you are trying to go (10 gallon and under).

6. Hillstream Loach

Quick Stats
  • Temperature: 20-24c ; 68-75F
  • PH:7-8
  • Size: Up to 3inches

The Hillstream Loach is an awesome little fish if you’re going with a more cooler water tank. Just as their names suggest, they come from fast-moving water such as streams and rivers. The two key elements to keeping a happy loach are to have strong water current and colder tank temperatures as they require very high oxygen levels.

Aside from algae, just like most algae eaters, they enjoy the occasional algae wafers and my personal favorite blood worms. Although there are several varieties of these little guys, most likely your fish store will only be carrying the spotted type. If you want to splurge you can find other varieties online and ship them to you but I probably wouldn’t for just a loach.

Oh lastly, they are very peaceful fish and should be kept with similar temperament aquarium buddies!

7. Whiptail Catfish, AKA Twig Catfish

Quick Stats
Temperature: 22-26c ; 73-79F
Size: Up to 6inches

The Whiptail catfish is a fish I am slightly biased towards as it hails from the lakes and rivers of the Amazon. Unfortunately for me, I haven’t seen these beauties at any of my local fish stores, but enough about me. They pretty much look like as their nickname suggests, a very long and skinny twig.

I find it kind of interesting that they have an elongated nose but have a sucker mouth. And we all know what that sucker mouth is for, eating up delicious algae and leftover food. They are however once again a more peaceful fish and it’s highly recommended to have some kind of rock work or driftwood for hiding spots as they can be easily stressed.

If you’ve ever wanted one of those twig insects as a kid well, here’s a slightly similar aquatic version. Oh the last thing, they can grow up to 6 inches so beware! No small tanks for these guys.


I tried to mix up both useful and unique algae eaters into the list. Do you have any suggestions? Post them in the comments below!

My name is James, and I’m in love with aquariums and fish since I was 12 years old. Back then my dad gave me a goldfish, and it’s been 35 years learning about this fascinating hobby. I’ve had some freshwater aquariums, tried my hand with marine tanks for 10 years, and kept some reefs for a while too. Here in the website I try to share some of my knowledge and experiences on fish keeping.


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