One of the major annoyances to befall most fish keepers at some point or another is a major buildup of algae in their home aquariums.
A range of factors can cause an excess of algae, including too much light, too few water changes, improper filtration, and nutrient imbalances.
While it’s often worth making some adjustments to address the root cause of an algae buildup, and algae scrapers, glass cleaners, and a water change can go some way toward curbing the problem, some degree of algae in an aquarium is almost impossible to avoid.
So we’d generally recommend adding some algae eating residents to your community tank.
Before we get to our favorite algae eaters, here’s a tip: despite their name, never buy Chinese algae eaters for a community aquarium. While juveniles do eat algae, as they mature, they feed off the body slime of other fish. This generally leaves an open sore, which can get easily infected, and often kills them. So, stay away from Chinese algae eaters!
Now, without further ado, here are the 12 best algae eaters for home aquariums.
1. Siamese Algae Eater
Not to be confused with Chinese algae eaters (who should never be kept in a community tank), Siamese algae eaters are active, peaceful fish that do a great job clearing algae.
While they’ll happily munch their way through all kinds of algae, they’re especially fond of black beard algae, which not all algae eaters will touch. What’s more, they eat algae without damaging plants, which makes them perfect for planted aquariums.
In fact, they tend to prefer living in tanks with live plants, especially those with flat, broad leaves for them to rest on.
As well as the algae they consume, Siamese algae eaters thrive on a varied diet of flakes or pellets, fresh vegetable matter, and live or frozen proteins (blood worms, mosquito larvae, etc.).
Reaching up to 6 inches long, these aren’t the smallest of fish, so you need to make sure you provide them with enough space, especially if you keep more than one. Siamese algae eaters should be kept either alone or in a group of five or more, since smaller groups may fight among themselves.
2. Bristlenose Plecostomus
For the average fish keeper, bristlenose plecos are a much better choice than the more widely-known common pleco. This is because bristlenose plecos only reach around 5 inches in length, compared to common plecos that can reach up to 20 inches long.
Due to their much more manageable size, bristlenose plecos are possibly the best algae eaters for small and medium aquariums. Any tank of around 30 gallons or more is suitable. Although, of course, the more additional fish you keep, the larger your tank will need to be.
As extremely peaceful fish, these little plecos are happy to mind their own business, eating algae all day. That said, it’s not advisable to keep two male bristlesnoses together, as they’re likely to become territorial and fight.
Despite all that algae-eating, algae alone won’t provide your bristlenose pleco with a balanced diet so they’ll need some supplementary feeding.
Algae wafers and sinking pellets designed for bottom feeders are both good choices. You may also want to try blanched vegetables and a small amount of meaty foods since their diet should be composed of around 15 percent protein.
Bristlenose plecos enjoy hiding out in shaded areas during the day, so you must give them some places to retreat to, such as caves, pieces of driftwood, or planted areas.
3. Cherry Shrimp
It’s not just fish that eat algae, so if you want a more diverse tank, why not consider adding some cherry shrimp?
Not only are these little guys excellent at clearing unwanted algae, but their bright red color also makes a striking addition to any aquarium.
Cherry shrimp are dedicated scavengers, picking up all kinds of minute pieces of food and other detritus that falls to the bottom of the tank. When this doesn’t get cleaned up, it can lead to more algae growth, so cherry shrimp actually help prevent more algae from forming, as well as eating the stuff that’s already there.
Since they only measure around 1.5 inches long, cherry shrimp don’t take up much room and can comfortably fit in a small single-species tank or a more substantial community aquarium, as long as you’re careful who you house them with.
Be cautious when selecting tank mates for cherry shrimp. While they’re peaceful and won’t cause an issue with any of your tank’s existing residents, they’re likely to end up as dinner for larger fish, so only house them with small, laidback fish species.
They do well in groups of their own species — we wouldn’t recommend keeping them alone.
Also known as doctor fish, garra are enthusiastic algae eaters native to the fast-flowing streams of Indonesia. As such they like to have a decent current in their tank, so you’ll need a strong powerhead or filter to keep them happy.
These are the same type of fish used in salons for pedicures, but they’re much better adapted to eating algae than the skin off people’s feet.
They’re often overlooked for being too drab, but certain subspecies, such as the panda garra, have more interesting colors and markings. Besides, looks aren’t everything, and these fish are a pleasure to watch going about their business.
These are social fish that should be kept in groups of five or more — those kept alone tend to attack other similar-looking fish.
Measuring roughly 3.5 inches long, garra aren’t huge fish, and a group can live in a 25-gallon aquarium, though you will need a larger tank if you’ll also be housing other species.
Although they’ll clear plenty of algae, they’ll need supplemental feeding to keep them in good condition. Offer a range of foods such as bloodworms, mosquito larvae, and algae flakes.
5. Otocinclus Catfish
Thanks to their small size and peaceful nature, otocinclus catfish (more commonly known as “oto catfish” or simply “otos”) make excellent additions to a community tank when you need to deal with an algae problem.
Although they like to be kept in small groups of three to five, they only reach up to 2 inches in length, so you can find room for them in most community tanks of 30+ gallons, as long as all the other residents are peaceable sorts.
What’s more, their small size allows them to get into nooks and crannies where larger fish wouldn’t fit, making them one of the best algae eaters for heavily ornamented tanks with spaces where alge may bloom that’s hard to reach. This means, even the awkward corners and far reaches of your tank will be cleaned of algae.
Since they don’t eat most live plants, they’re excellent for planted aquariums, where you might worry about other algae eaters destroying your favorite specimens. The only exception is Amazon sword plants, which they will sometimes take a nibble out of.
In addition to the algae they eat, you should supplement their diet with algae flakes and fresh green vegetables, such as small slices of zucchini.
6. Ramshorn SnailRamshorn snails are so-called for their attractive tightly curled shells that resemble a ram’s horn.
These small snails reach just 2 cm long, meaning they’re ideal residents even for small aquariums. They mostly eat algae found on plants, rocks and other decorations, and aquarium glass, though they’ll also chow down on leftover food and other detritus on the floor of the tank.
The good news for planted aquariums is, unlike most other algae eating snails, they won’t eat live plants unless there’s a real shortage of algae. You should also supplement their diet with a range of foods, including fish flakes or pellets, algae wafers, and pellets designed for bottom feeders.
Like all snails, they require alkaline water of at least 7 pH for proper shell formation, so it’s important to keep a close eye on the levels of acidity in your water. It may also be wise to offer some calcium supplements, as calcium is essential for keeping shells healthy.
Ramshorn snails will generally mind their own business, so you don’t have to be too picky about tankmates. However, large fish, such as cichlids and loaches, are likely to eat them, which means it’s better to keep them in tanks with smaller fish.
Unlike some snails which breed rapidly, ramshorns tend to be slow breeders, so you shouldn’t find your tank overrun with them.
7. Florida Flagfish
Also known as American flagfish, Florida flagfish aren’t our first choice due to their less than peaceful temperaments, but they’re happy to consume hair algae, which not many algae eaters will.
If you’re keeping them for their looks, note that males of the species are much more colorful than females. Juveniles sometimes look drab at first, but once settled they’re quite striking, especially kept with a dark substrate.
Since they’re native to densely vegetated streams and ponds in subtropical areas, they like to live in well-planted tanks at a slightly lower temperature than many tropical fish. As such, you’ll have to be careful to choose tankmates that have the same specific water requirements.
They can be slightly quarrelsome and have a tendency to nip fins, so keep them with other fish who can hold their own and who don’t have long flowing fins.
Although Florida flagfish only reach around 2.5 to 3 inches long, they prefer to be kept in groups of five or more, so be sure you provide them with enough room to thrive.
In addition to the algae they eat, you’ll need to offer them a varied diet of flakes or pellets, vegetable matter, and a range of meaty foods, such as brine shrimp and bloodworms.
8. Molly Fish
Although mollies won’t eat as much algae as some of the others on this list, this popular species do consume a fair amount of the green stuff.
If you have a severe algae problem, don’t expect mollies alone to cure it, but they make an excellent addition to community tanks, anyway, and will slowly scrape away at some of that algae. What’s more, they’re known to eat hair algae, which can become a real pain if it makes its way into your tank.
Mollies are livebearers and prolific breeders, so if you have a pair of the opposite sex, two mollies will soon become a whole shoal.
Depending on the type of molly you choose, these fish can reach anywhere between 4 and 6 inches long and should be kept in a minimum 30-gallon tank, though you should go for larger if you plan to keep a community tank.
Regarding tankmates, mollies are relaxed fish who should be kept with other peaceful fish of a similar size.
Feed your mollies a varied diet made up of a quality flake or pellet food, a variety of plant matter (such as zucchini and lettuce), and some protein-based foods (like brine shrimp and mosquito larvae).
9. Hillstream LoachWith their long, flattened bodies and sucker mouths, hillstream loaches are often mistaken for plecos. Although unusual and a pleasure to keep, hillstream loaches have specific care requirements and should only be kept by experienced aquarists who can provide them with the correct conditions.
Since they’re native to fast-flowing rivers, they require fast-moving, highly-oxygenated water to thrive. What’s more, they need their water to be slightly cooler than what’s usual for a tropical fish, which means it can be challenging to find them tankmates.
Although they’ll happily eat as much algae as your tank can provide, they require variety in their diet, so you’ll need to offer them additional food. They love to eat a range of vegetables — including cucumber, zucchini, and blanched spinach — but also require a commercial sinking pellet food and meaty foods, like daphnia and brine shrimp.
Hillstream loaches are peaceful and can be kept in groups of their own kind, though two males together may display some territorial behaviors.
10. Whiptail Catfish
Looking like plecos with long thin tails, whiptail catfish are striking and distinctive to look at. They have similar algae-eating abilities to plecos, too, but are much smaller than most species, usually measuring around 4 to 6 inches long, though you can find some larger specimens.
Whiptail catfish are extremely peaceful and can happily be kept in groups. In fact, it’s preferable.
Though they don’t need a lot of swimming space, they do need room to maneuver, so choose a tank large enough to accommodate them comfortably — around 20 gallons for the first whiptail and another 10 gallons per additional fish should suffice.
Since they’re native to highly vegetative areas, they’re well suited to planted tanks and aren’t likely to eat your plants or do any drastic rearranging. They like to have plenty of places to hide, so if you don’t keep them in a planted tank, be sure to place large rocks, caves, or pieces of driftwood to offer them some shelter.
As omnivores, whiptail catfish require a varied diet, so you’ll need to feed them a range of foods alongside their diet of algae.
A good quality sinking catfish or bottom feeder pellet is a good place to start. Supplement this with a variety of both vegetable and meat foods, such as zucchini, shelled peas, bloodworms, and daphnia.
11. Common Plecostomus
Although we warned against common plecos earlier in this article, they can make a good algae-eating addition to your tank if — and only if — you have a very large aquarium.
Since these behemoths can grow up to 2 feet long, we wouldn’t recommend keeping them in an aquarium smaller than 100 gallons. A tank of this size is going to need a lot of algae removal, and luckily the huge common pleco is up to the task.
Although generally peaceful with other fish, common plecos are territorial with one another, so you should avoid keeping more than one in the same tank. They’ve also been known to suck on the sides of flat-bodied or fleshy fish, such as discus and goldfish, so avoid housing a common pleco with any fish that fit this description.
These nocturnal fish like to have plenty of hiding spots in which they can retreat during the day, so place rocks, driftwood, and so on. Keeping common plecos in a planted tank isn’t the best idea, however, as they will eat live plants.
Supplement their diet with sinking algae wafers or spirulina tablets and a range of fresh green vegetables.
12. Amano Shrimp
Although more subtly colored than the cherry shrimp, Amano shrimp are cute little guys that are highly amusing to watch in your aquarium.
At less than 2 inches long when fully grown, Amano shrimp can happily live in compact aquariums, though they can also be part of larger community aquariums, as long as you’re careful who you house them with.
The main thing to remember when keeping Amano shrimp is they’re highly vulnerable to predators, so should only be kept with small, peaceful tankmates — otherwise, they’re likely to end up on the menu.
Some of the ingredients found in plant fertilizers can be harmful to Amano shrimp, so it’s best to avoid keeping them in heavily planted tanks unless you’re willing to commit to frequent, aggressive water changes (of at least 30 to 50 percent at a time).
They’re happy to eat any algae other than blue-green and green spot algae and happily forage for leftover food and any other morsels that sink down into the substrate. However, you may need to supplement their diets with foods such as shrimp pellets and algae wafers.
And that concludes our roundup of 12 of the best algae eaters to keep in home aquariums.
Happy fish keeping!