7 Great Freshwater Algae Eaters (And One To Avoid!) (2023)

Algae is a constant problem in aquariums. Because of the problems it can cause, you may need to make sure your tank is stocked with a cleaning crew in addition to your flashy fish. There are many misconceptions about algae eaters, so read on for great ideas and things to avoid.

Table of contents

1. Common Plecostomus

7 Great Freshwater Algae Eaters (And One To Avoid!) (1)

  • Maximum Size:18-24″
  • Minimum Tank Size:50g
  • level of care:Beginner
  • Special Requirements:Driftwood

The Common Pleco is often sold to the unwary, who see them only as an algae eater. The truth is they are highly specialized catfish, living their lives in fast currents where their squeegee is a necessity to avoid being moved.

People often buy their Pleco when they are only a few inches tall. Very inexperienced aquarists sometimes have the impression that they fit into their aquarium. They won't; they continue to grow for years until they die in their own waste or reach their adult size.

Plecostomus are easy to keep. They eat garbage and also feast on algae. You should also keep them in tanks of driftwood since they grateon the woodto balance their digestive system. Without it, their stomachs don't function at 100%.

be plecostomusergvigorous for their size, especially when they exceed 6 inches (15 cm) in length. They are also armored, making them the only Plecostomus species that do well with cichlids and other aggressive fish.

They are a great option for those with larger tanks, but smaller tanks should miss out on these big, impressive fish. However, you are certainly out of options as there is a lot of variety in algae eaters for smaller aquariums.

2. Bristlenose Pleco

7 Great Freshwater Algae Eaters (And One To Avoid!) (2)

  • Maximum Size:4-6″
  • Minimum Tank Size:10 liter
  • level of care:Beginner
  • Special Requirements:Driftwood

The Bristlenose Plecostomus is a smaller variety of Pleco. While they are generally not the smallest, they are easy to find and care for. They are also much cheaper than some of the expensive Pleco species that are in the same size range.

(Video) Top 5 Algae Eaters to Clean Your Aquarium

Bristlenose Pleco is suitable for small tanks, but not nano-sized. They still need driftwood, but they also seem to be more prolific algae eaters than the regular Pleco. They are almost as ubiquitous as regular Pleco in stores today and have no other specialized requirements.

They are also great cleaners for larger community tanks if you add multiples to them. One per 20-30 gallons is a good number to shoot for when you need a cleanup crew. They are compatible with most fish and are generally quite hardy critters.

Their size, active nature and admittedly good looks make them a favorite for many. For beginner aquarists, they are the best option for algae eaters. That goes double for smaller tanks.

3. Otocinclus catfish

7 Great Freshwater Algae Eaters (And One To Avoid!) (3)

  • Maximum Size:1 ½ "
  • Minimum Tank Size:5 liter
  • level of care:Intermediate
  • Special Requirements:Old tank

Otos are used in most small planted tanks. Their size makes them great for hanging out in nanotanks, but many people struggle to get them to thrive.

The key to making sure Oto does well is understanding their needs. While Pleco actively eats algaeIndetritus, Otos live on algae and biofilm. Biofilm is onecontrollable partof each tank, but it does not begin to occur until the tank has stabilized after the cycle.

Otos are easy to care for…as long as the tank is mature. They eat a surprising amount of algae, but you shouldn't put them in a brand new tank because they won't have a food supply. Few will even take algae wafers.

Once the tank matures? They are excellent fish for cleaning things up. They are not really voracious eaters, but a trio per five gallons will keep things tidy in a balanced aquarium. Besides the usual suspects in invertebrates…well, they're essential.

4. Ramshorn snail

7 Great Freshwater Algae Eaters (And One To Avoid!) (4)

  • Maximum Size:1″
  • Minimum Tank Size:1 gallon
  • level of care:Complete newbie
  • Special Requirements:No

Of the common snail species, Ramshorn snails are the most beautiful and best algae eaters. They have a bad reputation in some circles, but the same traits that make them a nuisance also make them an excellent algae eater.

Ramshorns breed abundantly. Since they are hermaphrodites, you only need two snails to start breeding. And they will reproduce, these snails often lay tons of eggs, which hatch in a matter of days to create a bunch of miniature snails.

Depending on the tank, you may have more or less overcrowding. Many fish like to eat the small snails, creating built-in population control. However, in heavily planted tanks many will mature.

(Video) Top 10 Best Algae Eaters For Your Aquarium: Something For All Tank Sizes!

Test your nitrates if you see a sudden spike in snail population. High nitrates often make them reproduce more, making them a monitor for nutrient spikes in your tank's water column.

Ramshorns have a few color morphs. The pink and gray varieties are most common, but they can all interbreed. They are attractive in larger sizes, but population control is a must. If you can pull that off, they'll survive in all water conditions and make an efficient cleanup crew with no extra work.

5. Cherry prawns

7 Great Freshwater Algae Eaters (And One To Avoid!) (5)

  • Maximum Size:1 ½ "
  • Minimum Tank Size:3 liter
  • level of care:Beginner
  • Special Requirements:No

Cherry Shrimp orNeocardina davidiare the most common dwarf shrimp in the tropical aquarium hobby. They are easy to care for, vibrant and available in a wide variety of colors. All of that puts them at the top of the list for many aquarists.

Cherries are among the easiest creatures to care for. They are extremely hardy, breed profusely and do not need much food. They readily eat algae around the tank and also search through the bottom of the tank to find discarded bits of food.

There is strength in numbers here. In an established tank you can keep about 2-3 per gallon without adding significantly to the bioload. It is not uncommon for this number to reach 5-6 per gallon in dedicated shrimp tanks.

They are not the most prolific algae eating shrimp, that title belongs to the Amano Shrimp, but they are fun to keep and do great. You just need more per liter of water.

6. Nerite-slak

7 Great Freshwater Algae Eaters (And One To Avoid!) (6)

  • Maximum Size:1 ½ "
  • Minimum Tank Size:1 gallon
  • level of care:Beginner
  • Special Requirements:Hard water of calciumsupplementen

Nerite snails are loved for their striking patterns and large size. They have a hidden advantage for the aquarist who wants to take advantage of their ability to eat algae. However, they area bit tricky to breed. Essentially, you need brackish water.

That means you can buy a few Nerites without worrying about population explosions. Ramshorn and bladder snails become fully part of a tank's ecosystem, Nerites being about as far out of it as most fish.

Nerites are easy to care for. Plop them in and check them. However, you should keep an eye on their shells. They need a significant amount of calcium to form their carapace, and it will bleach and thin if the level is too low. A little spinach or kale solves the problem if your water isn't hard enough.

In general, Nerites are a low-impact algae-eating machine. They are not as prolific eaters as Ramshorns, but many people feel it is balanced as they will not breed unpredictably. Instead, give them a shot if you're worried about having to take stronger measures to control the population with other species of snails.

(Video) The 7 Best Saltwater Algae Eaters 🐠

7. Amano Shrimp

7 Great Freshwater Algae Eaters (And One To Avoid!) (7)

  • Maximum Size:2″
  • Minimum Tank Size:3 liter
  • level of care:Beginner
  • Special Requirements:No

Amano Shrimp have a reputation for being busy workers. It is also well deserved. It's rare to see an Amano sitting idle in your tank; they eat constantly. They are also mostly clear and provide minimal visual impact in cases where the green is the most important part of the tank.

Amano shrimp has another benefit for some. They don't breed like bee or cherry shrimp, both of which breed for as long as they live. Their breeding process isa little muchfor the casual aquarist.

Amano shrimp are hardy and do not require specialized care unless you breed them. They stay away most of the time, and they are better with slightly larger community fish than Cherry Shrimp due to their larger size.

They are a classic for planted tanks. Give them a try if you like plants but don't like the idea of ​​brightly colored onesNeocardin sp. Flighting around the tank. Their drab appearance belies a hard-working, prolific algae eater.

Avoid at all costs: the Chinese algae eater

7 Great Freshwater Algae Eaters (And One To Avoid!) (8)

One of the cruellest tricks of the aquarium trade was naming theGyrinocheilus aymonierias an algae eater. The technically accepted name is the Siamese Algae Eater, but most places I've seen call them the Chinese Algae Eater. The above gold variety is called the Gold Chinese Algae Eater, but habits and physiology are interchangeable apart from color.

They start cute. They grow quickly and often destroy all algae in an aquarium. Problems start when they hit about 3" and persist throughout the fish's life.

As they get older, they eat much less algae than they did when they were younger. Instead, they begin to switch to a carnivorous diet. Their squeegee isn't an adaptation to eating algae... it's an adaptation to its native environment of fast-moving streams.

They also become territorial and aggressive. They can kill fish much larger than themselves by sucking off their slime coating before feeding on the body. They are even worse with each other.

Are they fish without good qualities? No. They are fun to watch and housed alone or with suitable companions. They are tough fish.

But buying one as an algae eater will give you a big and aggressive headache. As if that wasn't enough…well, they stop eating algae as they get bigger, and eventually they will grow to be a foot long.

(Video) 6 AWESOME Aquarium ALGAE EATERS That Aren't Pleco Fish

Thereisa similar fish, that is aastonishingalgae eater. The flying foxcan be difficult to tell apartof the CAE and other species, but it is one of the best algae eaters available. It even eats brush algae! The problem lies in finding a real Flying Fox, as sometimes even the dealers don't know they are selling you the wrong fish.

Give CAE a pass unless you know what you're going for, and be extremely careful if you choose to add a Flying Fox to your tank.

Frequently asked questions about algae eaters

Do all aquariums need algae eaters?

Not necessary. Instead, you can focus on making sure you have the parameters right and cleaning up the small amount that will appear on its own anyway. That said, you'll need more frequent water changes and keep a closer eye on water chemistry.

When is algae bad?

When it is "blue-green algae" orCyanobacteriën.These mucus can be dangerous. Otherwise, algae isn't a bad thing; it's just there and can be a bit ugly. However, it can be a good indication of general nutrient levels and in an established tank they can often prompt a test. In a new tank, don't rely on algae to let you know what's happening.

Does algae make my aquarium stink?

You can, but odors are often the product of pollutants rather than the algae itself. If your tank is smelly, you need to up your water change game, rather than just drop some new snails in it.

What other algae solutions are there?

Algae almost always indicatesexcess nutrients. For example, brown algae are intrinsically bound to nitrates and often appear in large numbers when a tank first cycles before softening. Cyanobacteria usually indicate a lack of oxygen in the water, while green spot algae can indicate low levels of phosphorus or CO2. The biggest culprit I've seen is people leaving their tank lights on for too long; they keep it under 12 hours. 8-10 am is the sweet spot.

Are chemical solutions a good idea for algae?

Sheable toare, and it depends on how you define a chemical solution. What Ido notto recommend is to throw an algaecide in the pile and hope that it works. This only masks the underlying problem, and the decaying algae can only make things worse as time goes on. Changing nutrient parameters is a much better chemical approach, giving an aquarium just the little push it needs to reduce algae growth.

What is the best algae-eating fish?

I recommend the following:

  • 50 liter +:Ordinary Pleco
  • 10-40 liter:Bristlenose Pleco
  • <10 liter:Oto catfish

Those guidelines won't lead you astray, as all fish are relatively mild but strong enough to handle anything that can fit in the same tank.

Why didn't you recommend the Siamese Flying Fox?

If you know about the species, you probably know that copycats are more common than the actual fish. The Flying Fox is a great algae eater, possibly the best you can find for home aquariums, but I'm always uncomfortable recommending it to new aquarists. You should be able to tell it apart from both the Chinese algae eater and the Siamese algae eater, as well as other lookalikes. Do your research if they are your choice!

Organize your cleaning crew

Our cleanup teams have a very important job: they keep our tanks nice and clean. While they can't do it all on their own, they are often the first line of defense against algae in your tank. The fact that they clean up uneaten food is just a bonus. So, how are you going to arrange your cleanup crew?


7 Great Freshwater Algae Eaters (And One To Avoid!)? ›

Nerite Snails are known to eat every type of algae found in a fresh water aquarium, including the harder to eradicate ones such as Green Spot Algae and Green Beard Algae. They are bottom dwellers as well, so they can also help clean your substrate.

What eats algae in freshwater? ›

Nerite Snails are known to eat every type of algae found in a fresh water aquarium, including the harder to eradicate ones such as Green Spot Algae and Green Beard Algae. They are bottom dwellers as well, so they can also help clean your substrate.

What is the best fish for eating algae? ›

10 Best Algae Eaters for Freshwater Aquariums
  1. Reticulated Hillstream Loach. This oddball fish is one of the coolest-looking algae eaters you will ever see. ...
  2. Amano Shrimp. ...
  3. Nerite Snails. ...
  4. Cherry Shrimp. ...
  5. Otocinclus Catfish. ...
  6. Siamese Algae Eater. ...
  7. Florida Flagfish. ...
  8. Bristlenose Plecostomus.

What's the best algae eater? ›

Conclusion. Some of the best algae eaters are shrimp, snails, Otocinclus, Siamese algae eaters, and bristlenose plecos as most of them eat a wide range of algae and are community-friendly.

What is the easiest algae eater to keep? ›

A snail of many names, the Apple Snail (also known as the Golden Mystery Snail, Golden Inca Snail and Yellow Snail) are effective algae eaters and eye-catching tank inhabitants. Golden yellow in colour, these beautiful snails are easy to take care of and prefer sharing their space with other non-aggressive tank mates.

What kills algae in water? ›

Bleach kills algae and prevents it from growing. The appropriate amount is ¼ teaspoon for every gallon of stored water. Chlorine will also kill algae and keep your water safe for drinking or irrigation purposes.

What removes algae from water? ›

Use bleach to kill the algae. If you have a problem with algae, you can use bleach to kill it all. The ratio should be one-quarter teaspoon for each gallon in your tank. Bleach is great for killing algae (and other organisms that may lurk in your tanks) and for keeping it from coming back.

What kills algae but not fish? ›

Step 3: Use hydrogen peroxide (H2O2) to help clear pond water: Another thing that works great for algae control in fish ponds is hydrogen peroxide (and no, it won't kill your fish!).

What fish cleans the tank? ›

Suckermouthed catfish like Common and Sailfin Plecos, Bristlenose and Otocinclus all graze algae and will “clean” the tank of it, but they do also need food in their own right if they are to grow, stay healthy and thrive.

What kills algae without harming fish? ›

One of the best algaecides out there that is safe for fish is a peroxyhydrate granular algaecide (which comes under many brand names). This comes in a solid granule form, and when added to pond water, it oxidizes, which destroys algae growth!

What kills algae the fastest? ›

Chlorine is still one of the most effective killers of algae so doing a super-chlorination of 10-20 ppm of chlorine can go a long way towards wiping out the algae. Liquid chlorine is an ideal shock for algae because it is fast acting and does not add cyanuric acid (CYA) or calcium to the water.

What is the hardest algae to get rid of? ›

Black algae is a stubborn organism. Its protective outer layer sets roots into the surfaces it clings to. This makes it one of the toughest algae strains to get rid of. Black algae appears as black spots on pool surfaces.

What is a good clean up crew for algae? ›

Crabs, snails, starfish, urchins and sea cucumbers along with utilitarian fish like blennies and tangs are your best defense against nuisance algae.

How many algae eaters can be in one tank? ›

Add no more than 3 algae eaters at a time to make sure the filter can handle all the new action in the neighborhood. The chemical balance in your aquarium will change with every new fish you introduce, so check the tank's pH, ammonia, nitrite and nitrate levels regularly.

How often should algae eaters be fed? ›

Feeding Guide

Feed twice a day. To accommodate the slower feeding habits of most algae eaters, feed the amount of food your fish will consume within two hours.

What kind of algae kills fish? ›

Golden algae are unicellular organisms found in freshwater lakes, ponds, and rivers. Like the better-known blue-green algae (cyanobacteria), golden algae have the ability to produce a toxin that disrupts respiration in gill-breathing organisms like fish, crayfish, and some amphibians.

What naturally removes algae? ›

Barley straw. Barley straw is a natural way to fight algae. On contact with water, the straw starts to break down, and as it does so it releases peroxides into the water which combat algae. Available in mini bales, or as a concentrated extract of barley straw liquid, it's a natural way of chemically fighting algae.

What kills algae naturally? ›

Grab a brush and some baking soda. Bicarbonate, the active ingredient in baking soda, is an effective spot treatment to help kill the algae and loosen it from the wall.

What keeps algae away? ›

Perform water changes: The single most important way to avoid algae is to perform regular water changes. Change 10 to 15 percent of your aquarium water every week to lower nutrients in the water. This will remove the nitrate that accumulates in aquariums, which is one of the main fertilizers for plants.

Does vinegar stop algae? ›

If you have an algae problem, your best friend is white vinegar. White vinegar can quickly kill algae but is not harmful to birds, insects and the majority of plants. Use a mixture of one part water to one part white vinegar to spray down the area and kill the algae.

What prevents algae from growing? ›

Common methods to prevent algal blooms include aeration, chemical/biological additives, or ultrasonic technology. Although there are plenty of treatment solutions on the market, they all have their cons. For example, algaecides offer quick results but damage the entire water ecosystem.

Is vinegar good for removing algae? ›

Although a bleach solution or white vinegar can help kill green algae, in most cases this is not a suitable solution; the Algae can grow back very quickly.

Is hydrogen peroxide safe for fish? ›

Several species of fish are known to be sensitive to hydrogen peroxide, and the use of the chemical may be toxic to those species.

How do I stop algae build up in my fish tank? ›

Cut back on how much food you put in the tank to prevent algae growth. Change the water. While you shouldn't change the tank water all at once, changing 10%-15% of the water each week ensures that nutrient levels are balanced. Over time, nitrate and phosphate accumulates and can contribute to algae growth.

What kills aquarium fish fast? ›

Clove oil is a sedative which at high doses, can be used to euthanase small fish. Unlike veterinary anaesthetics, clove oil is readily available from most chemists. Around 0.4ml of clove oil per litre of aquarium water is sufficient to cause death in exposed fish.

Do you leave fish in tank when cleaning? ›

It's best to keep your fish in the fish tank when you clean. Removing them causes unnecessary stress for your fish, and you run the risk of accidentally hurting them. It is possible to keep your fish in the tank while you clean because you don't need to remove all the water to clean the tank properly.

How do you get rid of algae overnight? ›

You can get rid of algae quickly by vacuuming and brushing your pool, balancing your pool's water chemistry, and then shocking and filtering your pool water. Just be thorough as you clean your pool surfaces. If you leave behind even a small number of algae spores, it won't be long before they regrow and bloom again.

What is the most toxic algae? ›

Red tides, blue-green algae, and cyanobacteria are examples of harmful algal blooms that can have severe impacts on human health, aquatic ecosystems, and the economy. Algal blooms can be toxic. Keep people and pets away from water that is green, scummy or smells bad.

What algae won't brush off? ›

Yellow Pool Algae or Mustard Algae

It's the second most common algae you'll find in swimming pools and sometimes can be mistaken for sand or pollen that can collect in your pool. This algae is difficult to get rid off and won't be killed off by any normal dose of sanitizer (such as chlorine) or an algaecide.

What is the biggest algae ever? ›

Giant bladder kelp (Macrocystis pyrifera) is the largest alga species measuring up to 65 metres.

Should I add clean-up crew or fish first? ›

When Should I Introduce my Cleanup Crew? If you are cycling your saltwater aquarium with live rock (as most saltwater aquarists do) then you will want to add the cleanup crew right after the cycle is complete (before you add fish).

How often should you clean algae out of your tank? ›

At least once a month you should use an aquarium vacuum to clean the gravel and a sponge or scraper to remove excess algae from the sides of the tank. In addition, you should also test the ammonia, nitrate, and pH levels and keep a log to make sure they are steady from month to month.

What is the best clean-up crew for a 20 gallon? ›

For a 20-gallon tank, I typically start with 10 snails, one cleaner shrimp, and two hermit crabs. Five snails are herbivores and will clean the glass and rock, and the other five snails are detritivores and live in the sandbed and eat extra food and fish waste.

What kills algae in freshwater tank? ›

To get rid of green water, you can blackout the tank for at least a week, which is hard on your plants. Another option is to purchase a UV sterilizer, which will kill off the algae within two to three days.

How do you get rid of algae in a freshwater lake? ›

The most effective way to reduce algae, muck and other problems in a lake or farm pond is to increase aeration. And the best way to increase aeration is to install a bottom-diffused aeration system. Lake and farm pond aerators function in much the same way as the ones used in smaller water gardens.

How do you control algae in freshwater? ›

Here are some of the things you can do to reduce and manage algae in your freshwater aquarium.
  1. Stock algae-eating fish.
  2. Avoid overfeeding.
  3. Keep up with water change and tank maintenance.
  4. Manage artificial light in your aquarium.
  5. Avoid direct sunlight.
  6. Utilize live plants.
Apr 6, 2023

What kills algae immediately? ›

Chlorine is still one of the most effective killers of algae so doing a super-chlorination of 10-20 ppm of chlorine can go a long way towards wiping out the algae. Liquid chlorine is an ideal shock for algae because it is fast acting and does not add cyanuric acid (CYA) or calcium to the water.

Does apple cider vinegar stop algae? ›

Adding 1 tsp of apple cider vinegar per gallon of water will help prevent algae from growing in your bird bath. It makes the water slightly acidic which kills the algae. It's important to dilute the apple cider vinegar so that it isn't too strong.

How do you prevent algae in stagnant water? ›

Common methods to prevent algal blooms include aeration, chemical/biological additives, or ultrasonic technology. Although there are plenty of treatment solutions on the market, they all have their cons. For example, algaecides offer quick results but damage the entire water ecosystem.

How do you prevent algae naturally? ›


The main goal of a successful algae control plan is to limit and reduce the nutrients in the water that can cause unwanted algae growth. Avoid grass clippings, leaves, fertilizer and other nutrient loaded organic debris from getting into your water body.


1. Top 10 Secret Algae Eaters You Should Try #aquariumcoop
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