What Are The Fish That Clean Tanks – 12 Best Algae Eaters And

Written ByHoward Parker

Have you ever looked at your aquarium and felt overwhelmed by the green film on the glass or the debris settling on the sand? You aren’t alone, and many hobbyists often ask what are the fish that clean tanks to help lighten the workload.

I promise you that by choosing the right aquatic partners, you can create a self-sustaining ecosystem that stays clearer and healthier for longer. In this guide, we will preview the best algae eaters, scavengers, and invertebrates that act as your personal underwater janitorial crew.

Whether you are a beginner or an intermediate keeper, understanding what are the fish that clean tanks is the first step toward a thriving display. Let’s dive into the world of functional fish keeping and find the perfect match for your setup!

The Reality of a “Cleaning Crew” in the Aquarium

Before we list the species, we need to set some realistic expectations for your new aquatic helpers. No fish will ever replace the need for a siphon and a bucket, but they certainly make the job easier.

It is a common misconception that “cleaning fish” eat fish waste or poop; they do not. Instead, they focus on uneaten fish food, biofilm, and various types of algae that naturally grow in a tank.

Adding these fish also increases the bioload of your aquarium. This means you are adding more life that breathes and produces waste, so your filtration must be up to the task.

Understanding what are the fish that clean tanks and how they help

When we talk about what are the fish that clean tanks, we generally categorize them into two groups: algae eaters and bottom-dwelling scavengers. Each group serves a distinct purpose in your ecosystem.

Algae eaters focus on the surfaces of your glass, rocks, and plants. They prevent diatoms or hair algae from taking over your hardscape and suffocating your live plants.

Scavengers, on the other hand, are the “vacuum cleaners” of the substrate. They ensure that excess flakes or pellets don’t rot in the corners, which prevents ammonia spikes and keeps the water chemistry stable.

1. The Otocinclus Catfish (The Dwarf Sucker)

The Otocinclus, or “Oto,” is widely considered the king of algae eaters for small to medium-sized tanks. They are small, peaceful, and incredibly diligent workers.

These fish are famous for their ability to clear brown diatom algae almost overnight. They have a specialized mouth that allows them to rasp algae off even the most delicate plant leaves without damaging them.

However, they are social creatures and should be kept in groups of at least 6. They are also quite sensitive to water quality, so ensure your tank is well-cycled before introducing them.

2. The Bristlenose Pleco (Ancistrus)

If you want a classic “suckerfish” but don’t have room for a massive 2-foot monster, the Bristlenose Pleco is your best friend. They usually top out at about 4 to 5 inches in length.

They are fantastic at cleaning green spot algae from the glass and driftwood. The males are easily identified by the fleshy “tentacles” on their snouts, which look quite prehistoric!

One thing to remember is that these fish require real driftwood in the aquarium. They rasp on the wood to aid their digestion, so it is a functional necessity for their health.

3. The Siamese Algae Eater (SAE)

The Siamese Algae Eater is one of the few fish that will actually consume Black Beard Algae (BBA). This stubborn, tufty algae is the bane of many aquarists’ existence.

SAEs are active swimmers and need a bit more space, ideally a tank of 30 gallons or more. They are peaceful but can be quite fast during feeding time.

Be careful not to confuse them with the Chinese Algae Eater. The Chinese variety becomes aggressive as it ages and may stop eating algae altogether, preferring to suck on the slime coats of other fish.

The Best Bottom-Dwelling Scavengers

While algae eaters handle the surfaces, scavengers handle the floor. These fish ensure that detritus and leftovers are recycled before they can pollute the water column.

Choosing the right scavenger depends heavily on your substrate type. Many of these fish have delicate barbels (whiskers) that can be damaged by sharp or rough gravel.

4. Corydoras Catfish

Corydoras, or “Corys,” are perhaps the most popular bottom-dwellers in the hobby. They are exceptionally peaceful and spend their days snuffling through the sand for morsels of food.

They come in dozens of varieties, from the tiny Pygmy Cory to the robust Bronze Cory. They are schooling fish, so please keep them in groups of at least 5 or 6 to see their true personalities.

I always recommend using a sandy substrate for Corydoras. This allows them to bury their faces in the sand to find food without scratching their sensitive whiskers.

5. Kuhli Loaches

If you want something a bit more “exotic” looking, the Kuhli Loach is a fantastic choice. They look like small, striped eels and are masters of getting into tight crevices.

They are nocturnal, meaning they will do most of their cleaning while you are asleep. They are great at finding hidden pockets of waste under rocks or inside decorations.

Don’t be alarmed if you don’t see them for a few days! They love to hide, but they are hardworking members of any cleaning crew in a community tank.

Invertebrates: The Secret Weapons of Cleaning

Sometimes, the best answer to what are the fish that clean tanks isn’t a fish at all. Invertebrates like shrimp and snails can reach places that fish simply cannot.

These tiny helpers have a very low bioload, meaning you can add several of them without putting much strain on your filtration system.

6. Amano Shrimp (Caridina multidentata)

The Amano Shrimp is arguably the single most effective algae eater in the world. Named after the legendary aquascaper Takashi Amano, these shrimp are relentless foragers.

They will eat almost any type of algae, including string algae and hair algae. They are also much larger and hardier than the popular Cherry Shrimp.

Because they are larger, they are less likely to be eaten by fish, though you should still avoid keeping them with large cichlids or goldfish.

7. Nerite Snails

Nerite snails are the absolute best glass cleaners you can buy. They move slowly but surely, leaving a perfectly clean trail behind them on the aquarium walls.

The best part? They cannot reproduce in freshwater. This means you don’t have to worry about a “snail explosion” taking over your tank like you might with bladder snails.

They come in beautiful patterns, such as Zebra or Tiger stripes. Just keep an eye on your lid, as they are known to occasionally wander above the waterline!

How to Choose the Right Crew for Your Tank Size

Not every “cleaner” is suitable for every tank. When considering what are the fish that clean tanks, you must match the animal’s needs to your environment.

For a 10-gallon nano tank, I suggest a group of 6 Habrosus Corydoras and a few Nerite snails. This keeps the bioload low while maximizing the cleaning coverage.

In a 29-gallon or 40-gallon breeder, you have more flexibility. You could house a Bristlenose Pleco, a school of 8-10 Corydoras, and a dozen Amano shrimp.

Always remember that overcrowding leads to stress and disease. It is better to have a slightly “dirty” tank than a tank full of stressed, cramped fish.

Dietary Needs: Don’t Let Your Cleaners Starve!

One of the biggest mistakes beginners make is assuming their cleaning crew doesn’t need to be fed. If your tank is too clean, your fish might actually starve to death.

You should supplement their diet with sinking algae wafers or shrimp pellets. This ensures they get the vitamins and minerals they need to stay healthy and active.

I also love to offer blanched vegetables like zucchini or cucumber. Just slice a piece, boil it for a minute, and weigh it down at the bottom of the tank. Your Plecos and Otos will love it!

Remove any uneaten vegetables after 24 hours to prevent them from rotting and fouling the water. This is a great way to bond with your fish while ensuring they stay nourished.

Common Problems and Safety Steps

Adding a cleaning crew is exciting, but there are a few safety steps you should follow to ensure a smooth transition for your new pets.

First, always quarantine new arrivals. Even “cleaners” can carry parasites or bacteria that could infect your existing fish. A simple 2-week quarantine can save you a lot of heartbreak.

Second, be mindful of medications. Many algae eaters, especially shrimp and snails, are highly sensitive to copper-based medications. Always read the label before treating your tank.

Finally, check your water flow. Many of these species, like the Hillstream Loach or Otocinclus, come from fast-moving streams and appreciate higher oxygen levels and a bit of current.

FAQs About Fish That Clean Tanks

Do cleaning fish eat fish poop?

No, fish do not eat the waste of other fish. They eat uneaten food, algae, and biofilm. To remove fish waste, you must perform regular water changes and vacuum the substrate.

Can I have too many cleaning fish?

Yes. Every fish adds to the ammonia production in the tank. If you add too many, your beneficial bacteria won’t be able to keep up, leading to toxic water conditions.

Will my cleaning fish eat my live plants?

Most dedicated algae eaters like Otocinclus and Amano shrimp are completely plant-safe. However, some larger snails or hungry Plecos might nibble on soft-leaved plants if they aren’t being fed enough.

What is the best fish for hair algae?

The Siamese Algae Eater and Amano Shrimp are the top contenders for tackling tough hair algae. They have the right mouthparts to pull and consume the long strands.

Do I still need to clean the glass if I have snails?

While snails help significantly, they may miss spots. You will likely still need to wipe the glass occasionally during your weekly maintenance to keep it crystal clear.

Conclusion: Building Your Perfect Cleaning Team

Choosing what are the fish that clean tanks is one of the most rewarding parts of the hobby. It transforms your aquarium from a static box into a functioning, miniature ecosystem.

Remember to start slow. Add one species at a time and monitor how your tank reacts to the new bioload. Patience is the key to a successful and algae-free aquarium.

By combining the surface-cleaning power of Bristlenose Plecos with the floor-scrubbing antics of Corydoras, you’ll spend less time cleaning and more time enjoying your beautiful underwater world.

Don’t worry—if you ever feel stuck, just remember that every expert was once a beginner. Happy fish keeping, and may your tank always stay sparkling clean!

Howard Parker
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