Home | Aquarium Livestock | Algae in Freshwater Aquariums and Ponds: a Primer (Part II)

Algae in Freshwater Aquariums and Ponds: a Primer (Part II)

Hello, Frank Indiviglio here. Please see Part I of this article for information on using plants and bacteria to control algae. Today I’d like to take a look at some algae-eating fishes, snails and shrimps.

Sucker Catfishes (Plecostomus, Hypostomus, Loricarichthys spp.)
An incredible array of fishes consume algae, with these interesting beauties being among the best known. Larger sucker cats and Chinese sailfin sharks (see article below) can also be kept in outdoor ponds.

Thailand Flying Fox, Epalzeorhynchus kallopterus
This nicely marked fish consumes all types of algae, and is also fond of the flatworms that sometimes arrive in aquariums along with live plants.

Siamese Algae Eater, Crossocheilus siamensis
This fish is similar in appearance to other, less-effective species, and is sometimes sold as the “True Siamese Algae Eater”. It does well in schools, and consumes even the coarser varieties of hair and beard algae.

Chinese Hillstream Loach, Beaufortia kweichowensis
This small loach is one of my favorites. It has been compared to a flounder in appearance, but reminds me of the oddly-shaped torpedo rays.

This active loach is adapted to fast-flowing waters, and fares best in high oxygen environments. It is well-suited for removing algae from glass and plant leaves, and is rarely if ever bred in captivity…definitely a fish worth working with for those interested in breaking new ground.

Garra pingi pingi or Pingi Log Sucker, Discognathus pingi
Formerly rare in the trade, this stout East Asian bottom dweller has a huge appetite for algae of all types. Many aquarists find they must supplement its diet with algae wafers; those I have kept took pre-soaked kale as well.

This is another species which would make a nice breeding project, as only wild-caught animals are available at this point.

Algae Eater, Gyrinocheilus aymonieri
The “standard” algae control fish in smaller aquariums, the taxonomy of this interesting species is somewhat of a mystery. While typically reaching 4 inches in length, I recall receiving shipments of individuals that topped 11 inches. I hope to keep some in an outdoor pond in the future, to see if the increased water volume might spur additional growth.

Algae eaters relentlessly comb rocks, glass and plant leaves for algae, and will take leftover fish flakes as well.

Freshwater Shrimp
Almost all of the dozen or so species currently available favor algae as food. Particularly attractive is the cherry shrimp, Neocaridina denticulata sinensis. Given proper care (please see article below) they will breed prolifically, with a large group making for a spectacular display.

Freshwater shrimp will co-exist with the fish mentioned above, but will, however, be harassed or eaten by fishes with carnivorous tendencies.

A number of snails live almost entirely upon algae, but many consume plants as well. Apple snails can eat a surprising number of plants overnight, while olive Nerites (please see article below) take only algae and do not reproduce in fresh water. The Japanese trapdoor snail is also a good choice, but needs warm, well-filtered water.

Further Reading
To learn more about some of the creatures mentioned above, please see the following articles:
Freshwater Shrimp

The Chinese Sailfin Shark

The Olive Nerite

Please write in with your questions and comments. Thanks, until next time, Frank Indiviglio.


  1. avatar

    Great article! I have a question I hope you can answer, though. Can any of these (particularly the sucker catfish) be kept in an outdoor pond throughout the winter? Also, would they get along well in a rather shallow pond (I’m not sure the exact depth – too shallow to keep koi is all I know) with goldfish?

  2. avatar

    Hello, Frank Indiviglio here.

    Thanks for the kind words, much appreciated.

    Sucker cats and the other fishes mentioned do very well in outdoor ponds during the warmer months, but cannot overwinter outdoors in temperate regions. Shallow water is fine, as long as it does not over-heat during the summer.

    Except for shrimps, all will co-exist with goldfish, but you’ll need to make sure that the goldfishes do not consume all the food (algae alone may not be enough to support larger sucker cats, so you’ll need to supplement them with algae based tablets and greens such as cucumber and kale).

    Native snails can be overwintered outdoors, if the water does not freeze to the bottom of the pond (they will survive if goldfishes survive).

    Good luck and please let me know if you need further information. Introducing sucker cats to outdoor ponds takes time and care (the actual introduction process), so please feel free to write in for details if you plan on trying.

    Best regards, Frank Indiviglio.

  3. avatar

    I have read both articles, my question is I am working with a 125 galon tank with african cichlids. Plants are difficult to keep growing even though I am persistant in replacing them. Lately I am finding algie in the tank. Most algie eaters will not survive with the cichlids. do you have any ideas. I would love a fully planted tank but I am finding that to be very costly. My tetra tank is doing great and plants thrive in it. Please help.

  4. avatar

    Live Plants and Africans don’t often mix well, as you already know. What types of plants are you trying to keep? Besides the disruption that the cichlids can cause, the water quality (hardness/alkalinity/pH) is not suitable for many plant species. Anubias sp. are probably the most common and adaptive plants for cichlids as are Java fern. There is a great article on cichlid forum about plants an cichlids you may want to read for more info (http://www.cichlid-forum.com/articles/plants_101.php). As for the algae, that is probably a lighting or maintenance issue. Be sure your bulbs are not too old (should be replaced every 9-12 months), or algae will thrive and the plants will diminish. Also be sure to minimize nitrates and phosphates by doing regular water changes, siphoning substrate, and being careful not to overfeed. Some snails will tolerate the water conditions and the cichlids to control algae, and some cichlid species will eat it too, but it will depend on the species you have in the tank already whether these are solutions for you.

  5. avatar

    There are indeed quite a lot of freshwater tank algae that is rampant in our tanks. We deem it necessary to carefully determine what type of algae it is to facilitate and provide the correct treatment plan.

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About Frank Indiviglio

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Being born with a deep interest in animals might seem unfortunate for a native Bronxite , but my family encouraged my interest and the menagerie that sprung from it. Jobs with pet stores and importers had me caring for a fantastic assortment of reptiles and amphibians. After a detour as a lawyer, I was hired as a Bronx Zoo animal keeper and was soon caring for gharials, goliath frogs, king cobras and everything in-between. Research has taken me in pursuit of anacondas, Orinoco crocodiles and other animals in locales ranging from Venezuela’s llanos to Tortuguero’s beaches. Now, after 20+ years with the Bronx Zoo, I am a consultant for several zoos and museums. I have spent time in Japan, and often exchange ideas with zoologists there. I have written books on salamanders, geckos and other “herps”, discussed reptile-keeping on television and presented papers at conferences. A Master’s Degree in biology has led to teaching opportunities. My work puts me in contact with thousands of hobbyists keeping an array of pets. Without fail, I have learned much from them and hope, dear readers, that you will be generous in sharing your thoughts on this blog and web site. For a complete biography of my experience click here.