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10 Cold Water Algae Eaters For Ponds And Aquariums!

The popularity of keeping aquariums is skyrocketing right now and it’s not surprising that we are seeing so many questions from beginners new to keeping aquariums asking about how they are able to offer the best possible care for their fish.

Without a doubt, the most common questions that we see people asking about time and time again is based on keeping the algae in an aquarium to an absolute minimum be it a hot or cold tank.

With there being plenty of algae eater options for warm and hot tanks with there being a large amount of information online already, we have decided to publish this article going over the best cold water algae eaters that you are able to use.

Depending on your needs, the featured algae eaters in this list should easily be able to keep the algae in your cold water aquariums or ponds to a minimum with ease.

Please note that the water temperature between an unheated aquarium that is kept indoors at room temperature and an outdoor pond is very different.

This will change the type of cold water algae eater that you are able to use for each situation so as we work our way throughout the article, we will go over if each of our featured algae eaters are well suited for just cold water aquariums or if you are also able to use them in an outdoor pond too.

Are There Any Cold Water Algae Eaters?

There are plenty of cold water algae eaters available for both room temperature aquariums and outdoor cold water ponds.

Although there is some cross over between the two, most outdoor ponds will usually be limited to snails unless you live in a warm area. Options range from plecos, shrimp, snails, and mollies with a few other less common algae eaters also being suitable.

Depending on your aquarium size, there are usually a number of excellent cold water algae eaters for aquariums with hillstream loaches, cherry shrimp, and mollies often being classed as some of the best options.

If you live in a warm area that is around 70°F/21°C year round then you are often able to use all of our featured cold water algae eaters in an outdoor pond without issue.

If you live in an area where the outdoor temperature does fall below 70°F/21°C, even if its just by a small amount and for a few weeks of the year, you are pretty much restricted to using snails as your cold water algae eaters.

In our opinion, ramshorn snails are the best cold water algae eaters for outdoor ponds in colder areas due to being robust and able to take temperature fluctuation well.

Hillstream Loach

Hillstream loaches are an excellent cold-water algae eater option for aquariums that are kept at room temperature due to the fish needing a constant temperature of around 72°F/22°C.

Hillstream loaches are omnivores and grazers meaning they will eat large amounts of algae, biofilm, and discarded food in your cold water aquarium to help keep the tank clean.

They usually need a tank of at least 50 gallons when fully grown though and you can usually find hillstream loaches for around $15 to $20 per fish.

Cherry Shrimp

Cherry shrimp are the best cold water algae eater for smaller aquariums and ponds due to being able to live in tanks as small as 5 gallons without issue.

They can work well in both aquariums and ponds as they are comfortable in temperatures of 57–84°F/14–29°C and will eat a surprisingly large amount of green and brown algae for their small size.

You can usually pick up cherry shrimp for around $3 to $5 per shrimp with multiple shrimp usually being recommended for larger ponds and aquariums.


Mollies can be a good algae eater option for anyone who wants to use a “pretty” fish as their algae eater of choice but they do have downsides.

Although mollies are not officially classed as algae eaters, they will eat algae but in much smaller amounts than the other features options in our article.

They also usually need a warmer temperature than the other options too with a minimum temperature of 71°F/21°C being required.

Although millies are popular, there are definitely better cold water algae eaters but you can usually find them for around $3 to $10 per fish depending on their color and pattern.

Ramshorn Snail

Ramshorn snails are the best cold water algae eater option for ponds due to being comfortable in temperatures of 65°F/18°C while still being tolerant of temperatures colder than that with ease.

Although ramshorn snails are small, they eat a huge amount of algae per snail relative to their size while also being very cheap and often being $1 to $2 per snail.

The general rule of thumb is to have one ramshorn snail per 5 gallons of water in your pond or aquarium to keep algae to a minimum.

Amano Shrimp

Amano shrimp are another good cold water algae eater option for room temperature aquariums due to being comfortable in waters of 65°-85°F/18°-29°C.

Just like the other shrimp on our list, amano shrimp can also consume a huge amount of algae relative to their small sizes while also usually only costing between $1 and $2 per shrimp making them a very budget-friendly cold water algae eater option.

Similar to ramshorns snails, the general rule of thumb is to have one amano shrimp per 5 gallons of water to keep algae to a minimum but in tanks of 10 gallons or more, you can use two shrimp per gallon if algae builds up quickly.

Nerite Snail

Although nerite snails are a commonly used cold water algae eater, they do usually need a water temperature of at least 70°F/21°C meaning that they should only really be kept in aquariums or ponds in warmer areas as the average room temperature is lower than their recommended temperature.

Nerite snails are excellent algae eaters though and will consume a large amount of algae in a short period of time while also being a budget-friendly option and usually being around $1 to $4 per snail.

Bristlenose Plecostomus

The bristlenose pleco is a very popular cold water algae eater that usually needs a water temperature of at least 65°F/18°C making it ideal for aquariums at room temperature as well as ponds in warmer areas.

A fully grown bristlenose pleco will usually require a tank of at least 20 gallons with 25 gallons usually being recommended with other fish.

They are also more expensive than some of the other algae eaters on our list coming in with a price tag of $7 to $10 per fish depending on your area.

Otocinclus Catfish

Otocinclus catfish are not strictly a cold water algae eater and should only be kept in room temperature tanks in warmer areas due to them requiring a minimum temperature of 72°F/22°C.

They can do well in tanks as small as 10 gallons but usually do better in larger tanks, especially if you are keeping other fish with the otocinclus catfish eating large amounts of soft algae build up.

You can usually get otocinclus catfish for around $5 making them a relatively budget-friendly option considering how much algae they will actually eat.

Clown Plecostomus

Clown plecos are another algae eater that should only be really kept in warmer areas due to requiring a minimum water temperature of 73°F/23°C.

They do tend to eat a decent amount of algae for their size though and a single clown pleco is often able to keep the algae build up in a 20 gallon tank to a minimum without any other algae eater being in the tank.

Clown plecos can range from $10 up to $20 depending on the supply and demand of the fish as well as the time of year making them one of the more expensive algae eaters on our list.


That brings our article going over our recommended cold water algae eaters for ponds and room temperature aquariums to an end. We hope that you have been able to find the right cold water algae eater for your needs and have been able to find your next addition to your tank. In the majority of cases though, most of our readers can easily use snails or shrimp to keep their algae build up under control but many people tend to prefer to use fish due to their better looks for the visual aspect of the tank.