Algae-Eating Fish Species for a Healthy Pond

Algae are a natural part of the aquatic ecosystem, but they can overgrow and leave your pond looking like a slimy green mess. Luckily, you can control algae naturally with the right algae-eating fish. Many fish species eat different types of algae, including green algae, black beard algae, hair algae, and diatoms.

In this guide, we explore the 10 best algae eaters, what they eat, and how else you can manage algae growth.

Why Does Your Pond Need Algae Eaters?

Surplus nutrients, too much direct sunlight, lack of competition, and stagnant water can contribute to rapid algae growth in your pond. Without effective algae eaters, you’ll end up with stubborn algae blooms that smother plant leaves, coat rocks, and starve fish of oxygen.

While chemical treatments provide short-term solutions, fish that eat algae are a more permanent, eco-friendly option. You can couple them with other methods, such as proper aeration and plant cover, to create a thriving, low-maintenance ecosystem

The 10 Best Algae-Eating Fish and Invertebrates

1. Siamese Algae Eater (Crossocheilus oblongus)

This thin, long fish is always on the move, grazing on driftwood, plant leaves, and your pond's walls. It's known for eating hair algae and black beard algae, and gets along with many species.

They also feed on stubborn types of algae that other fish ignore, and thrive in a well-oxygenated setting that promotes their activity level and health.

2. Common Plecostomus (Large Pleco)

The plecostomus is a heavy-duty algae eater. This large algae-eating fish grows up to 24 inches in large ponds and can handle thick biofilm, green algae, and detritus on pond walls and floor.

They're well-suited to ponds with circulation, minimal territorial fish, and plenty of room to swim. This makes them a top choice for golf course and business park ponds that need to be kept clean without frequent manual scrubbing.

They do produce a lot of waste, so pairing them with an aerator is a fantastic way to keep ammonia and nutrient levels in check.

Shop our Kasco Pond Aerators to complement these large algae eaters.

3. Chinese Algae Eater

The Chinese algae eater begins life as a competent cleaner, but its behavior changes as it matures. Juveniles are excellent at removing green algae from all surfaces. However, as they age, they can become territorial, especially in small spaces.

That's why they remain a good option for larger ponds that offer plenty of space and filtration, despite their shifting diet and attitude. Support these algae eaters with aerators for exceptional pond clarity.

Got a larger pond? Shop our aerators today.

4. Twig Catfish (Farlowella spp.)

If you want to control algae in your pond's ecosystem with minimal disruption, twig catfish are a gentle option. They can control submerged logs of soft algae types without damaging your aquatic plants.

Twig catfish are a great match for well-maintained koi ponds and water gardens. While they are less aggressive than other algae-eating fish, they are very focused and persistent.
It's important to maintain well-oxygenated conditions because of their sensitivity to water quality. Use aerators to stabilize oxygen levels and prevent nutrient build-up that feeds algae growth.

5. Amano Shrimp

Amano shrimp have earned their reputation as excellent algae eaters in the aquatic world. They feed on hair algae, black beard algae, residual food, and even plant debris.

They’re compatible with otocinclus catfish, small catfish, and any non-territorial fish, and ideal if you need long-term clarity without chemicals.

Want to maintain healthy, active shrimp? Use a mini aerator to maintain highly oxygenated water, especially in hot climates or small indoor ponds.

Shop our Scott Aerator Bubble Pro Mini today. 

6. Cherry Shrimp

These red shrimp provide dependable algae control for planted tanks. They are the best for controlling green algae and surface slime buildup in low-flow conditions.

Cherry shrimp breed easily to produce tiny colonies that can manage algae in the long run. They make great small ponds, nano tanks, and aquarium inhabitants where larger algae eaters can’t fit.

7. Nerite Snails

Nerite snails are the ultimate precision cleaners for eliminating algae without the danger of overpopulation. They feed on diatoms, green spot algae, and film algae on surfaces left behind by fish and shrimp.

Since they cannot reproduce in freshwater, they will not overcrowd your tank like other snail species. An adequate population of nerites can make a tank or indoor pond immaculate while augmenting the efforts of shrimp and fish.

8. Molly Fish

Commonly known as mollies, these are active grazers that naturally feed on soft green algae and biofilm. While known for their social behavior and breeding ease, they’re also excellent algae eaters.

In ponds, they’re best suited to tropical or summer conditions where cooler waters aren’t a factor. Use pond heaters during winter to stop them from freezing and protect their life.

9. Goldfish

Many goldfish varieties eat algae growth on rocks, plants, walls, and décor. They’re opportunistic feeders, often picking at green algae when nothing else is immediately available.

Since goldfish produce a lot of waste, you must support them with strong water movement and filtration. A cost-effective aerator is an excellent pairing for goldfish ponds to help maintain oxygen levels and reduce nutrient buildup.

10. Koi

As the royalty of pond fish, koi eat a range of algae types, leftover feed, and plant debris, keeping your pond's surface and shallow zones looking fresh.

However, koi ponds require careful planning due to their size and metabolic output. Use pond fountains and aerators to keep oxygen levels high and discourage algae growth. Aeration helps stabilize temperatures and distribute oxygen to keep koi healthy and active in every season.

Building a Team of the Best Algae Eating Fish

Mixing species of fish can help tackle various algae types. For example:

• Use Siamese algae eaters for black beard algae.
• Otos and nerite snails for film and diatoms.
• Amano shrimp for hair algae and detritus.

However, algae eaters are a supplement, not a standalone solution. For best results, combine them with the following:

• Aeration system: Our collection will transform your pond into a thriving ecosystem with optimal oxygenation, temperature regulation, and algae control. They’re also energy efficient and easy to install.
• De-icers: Our dock de-icers use heating elements to prevent ice formation and promote water circulation. This improves water clarity and prevents stagnant conditions.
• Solar powered aerators: These are easy to set up, eco-friendly, and cost-effective. They get rid of stagnant water and reduce algae to enhance the health of your pond.

How to Control Algae and Support Algae Eaters

• Avoid direct sunlight: Floating plants block excess light.
• Control feeding: Surplus food means more nutrients for algae.
• Use a timer: Aerators work best on consistent schedules.
• Clean ponds manually when needed: Stubborn algae sometimes need a push.

Read this guide on How to Get Rid of Algae in Ponds for more hands-on tips.

Frequently Asked Questions

What Are the Best Algae Eaters for a Small Tank?

Otocinclus catfish, nerite snails, and cherry shrimp are perfect for small home aquariums. They're the most suitable to manage green algae, diatoms, and soft film without overwhelming your tank.

Which Fish Eat Algae in Ponds?

If you have an outdoor pond, excellent algae-eating fish include Siamese algae eaters, plecostomus, goldfish, and koi. Siamese flying foxes and common plecos are also beneficial, particularly in bigger ponds. Their viability, however, depends on temperatures, proper filtration, aeration, and controlled feeding.

What are the Best Freshwater Algae Eaters?

The best freshwater species for algae control include bristlenose plecos, amano shrimp, otos, and Siamese algae eaters. These are excellent maintenance crews that eat a wide range of algae.

Are You Ready to Control Algae?

These fish, shrimp, and snails that devour algae are your silent cleaners that work behind the scenes to bring back your pond’s clarity and balance. If you pair the proper combination of top algae-eating fish with quality pond equipment, you'll spend less time cleaning your pond and enjoy crystal-clear water and a healthy aquatic life.

Shop at Your Pond Pros today for the best equipment to complement these algae eaters.