That Fish Blog – Aquarium Advice and Information

Finding the perfect new addition to an aquarium is often like finding the Holy Grail to many aquarists. We all want the perfect little helper to keep the tank clean so there’s less work for us to do (and so our tank is cleaner and healthier, of course) but many “algae eaters” get too large for smaller aquariums and many others like the group of fish known as “plecos” don’t even eat algae at all. So what are the best plecos and algae eaters for small freshwater aquariums? Here are a few of our favorites that are some of the best choices for smaller community aquariums:

 

Bushynose & Bristlenose Plecos (genus Ancistrus)

• PROS: Lots of variety in color and pattern, small size, vegetation-heavy diet (including algae), community-friendly.
• CONS: Some species grow larger than others, needs meaty foods as well, underfed fish may eat live plants.
• BEST SUITED AS: A community algae-eater and bottom-feeder.

 

Plecos from the genus Ancistrus usually have “Bristlenose” or “Bushynose” somewhere in their common names, a nickname that comes from the whisker-like frills that develop on most adults. They are usually more prominent in adult males but some females may get them too in some species. Different species in this group have different requirements, but they are generally among the smallest plecos. While they eat some meatier foods as well, most appear to eat mostly vegetation.

 

 

Clown Pleco (Panaque maccus L104)

• PROS: Small size, easy-going temperament, fairly wide-spread diet.
• CONS: Need driftwood for grazing, not primarily an algae-eater.
• BEST SUITED AS: A general clean-up bottom-feeder for community aquariums.

The Clown Pleco is a popular small pleco. As with other Panaque plecos, these fish are omnivores and feed about equally on plants matter and meatier foods. Panaque plecos are also unique in that they actually feed on driftwood as well; make sure you have driftwood décor in your tank for these fish to graze on.

 

 

 

Hillstream Loaches

• PROS: Eats algae, can be kept in groups, unique and unusual appearance.
• CONS: Needs high flow and pristine water, vulnerable to aggressive tankmates and poor water chemistry.
• BEST SUITED AS: A unique addition to a suitable community aquarium where it incidentally may help eat algae but isn’t the primary algae-eater.

Hillstream Loaches have flattened guitar-shaped bodies and are often mistaken for plecos. They cling to rocks in the fast-moving mountain stream where they come from much like plecos cling to surfaces. Hillstream Loaches need well-oxygenated and well-filtered tanks and don’t do well with nippy tankmates or in tank with less-than-pristine water quality. They do eat some algae however, as well as other detritus and leftover sinking foods.

 

 

Otocinclus Catfish

• PROS: Small size, safe for planted tanks, primarily algae-eaters.
• CONS: Can be sensitive to stress, can starve if they can’t find enough to eat.
• BEST SUITED AS: Algae-eating housekeepers in planted community aquariums.

 

There are a few very similar species that are commonly grouped together as Otocinclus Catfish (“Oto Cats”) or “Dwarf Suckermouth Catfish”. Most are brownish-grey in color with a black stripe but some like the Zebra Oto (Otocinclus cocama) have a more ornate pattern. These fish stay under two inches in length and are great for eating algae off of plants without harming the plants. They can be a bit finicky and sensitive though so only keep in a stable, healthy aquarium. They are also best kept in groups so plan tankspace accordingly.

 

 

Rubbernose Plecos (Chaetostoma sp.)

• PROS: Moderately small adult size, eats some algae, community temperament.
• CONS: Not a primary algae-eater, can be bulky for very small tanks.
• BEST SUITED AS: A general bottom-feeder for community tanks over about 30-45 gallons.

 

Like the Clown Pleco, Rubbernose Plecos are some of the most common smaller plecos available. They also have a very familiar pleco-like appearance that many novice aquarists associate with algae control. They are not exclusive algae-eaters however; this is another omnivore that needs about equal parts meaty food and plant matter. These fish are pretty middle-of-the-road overall: moderate adult sizes, eats diet for about half their diet, neutral coloration, moderate temperament.

 

 

Freshwater Nerite Snails

• PROS: Colorful shells, safe for plants, small size.
• CONS: Limited availability, may reproduce, may be vulnerable to predators.
• BEST SUITED AS: Algae-eating grazers for small planted aquariums.

 

Nerite Snails are popular for saltwater aquariums but some species are found in freshwater as well. These snails are much smaller than some of the other less-suitable and more invasive freshwater snails like Apple Snails or Trapdoor Snails. They mainly eat smaller algaes like the ones that cause spots on glass but usually won’t harm plants. These snails also appear to bred less frequently in most aquariums than the more common Apple Snails. Make sure the ones you get are from freshwater; a saltwater Nerite will not survive being moved to a freshwater tank.

 

Freshwater Shrimp (Caridina sp.)

• PROS: Safe for plants, small size, can be kept in groups.
• CONS: Limited availability, vulnerable to predators, very small.
• BEST SUITED AS: Algae-eaters for planted nano tanks with peaceful or no other tankmates.

Small freshwater shrimp like the popular Cherry Shrimp and Amano Shrimp can be ideal grazers, especially for nano tanks (under 1-2 gallons). Some are clear, some are colored or have colored markings and they can be kept in groups. However, most of these shrimp are very small; you may not see them often and can’t be kept with anything remotely predatory.      

 

 

 

As always, the best algae-eater for your tank depends on its tankmates, the size of the tank, the water parameters and other such factors but hopefully this helps give you some alternatives to fish that may be too big or otherwise unsuitable to your needs. If you need more help in making your best choice or have a favorite of your own, feel free to comment below!

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.

Snails
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.

Brandon here. Many aquarists that come through our fish room will ask what we recommend as algae eaters for their reef.  The answer is usually the same: snails, hermit crabs, or maybe a lawnmower blenny.  One of the most efficient algae eaters found on the reef is usually overlooked, the sea urchin.

Sea urchins are relatives of starfish and sea cucumbers, belonging to the phylum Echinodermata.  They are generally covered in hard spines for protection, little clawed arms called pedicellariae which are used to remove debris and detritus from the urchins’ skin and can also aid in protection, and tube like feet used for moving across the substrate.  Their mouths are surrounded by a structure called Aristotle’s Lantern, which is used for scraping rock and breaking food apart.  The Aristotle’s Lantern is what makes some urchins such efficient algae eaters.

While not all sea urchins eat algae, and not all that eat algae are desirable for a reef tank, there are a few that would make a great addition to the aquarium.  The Variegated Green Urchin, Lytechinus variegates, stays relatively small and clears live rock of virtually all types of algae.  One urchin that we use in some of our display tanks here at the store is the Tuxedo Urchin, Mespilia globulus.  These urchins also remain relatively small and do a number on different types of algae.  Another extremely efficient, algae-eating urchin is the Longspine Urchin, Diadema setosum.  These can grow very large, and have spines capable of puncturing skin and leaving a painful injury.

 Here are some urchins to avoid in the reef tank.  Rock-boring Urchins, Echinometra lucunter, do little to clean up algae.  They spend most of their time chewing holes in live rock.  Priest Hat Urchins, Tripneustes gratilla, are generally considered reef safe, and will even do some scavenging, but they can also grab immobile fish and inverts for dinner.  One urchin that we do not carry here at That Fish Place, the Flower Urchin, Toxopneustes pileolus, is very beautiful but can inflict a potentially deadly sting.  It is covered in what appears to be little flowers, but are actually pedicellariae.  These specialized pedicellariae have three jaws on the tip, each of which is hollow and filled with venom.  Upon contact they snap shut and inject venom into the skin, which causes extreme pain and even muscle paralysis, which could drown an unsuspecting diver.

Urchins are not for everyone.  While they will clean up most types of undesirable algae, they can also scrape coralline algae from the rock work, leaving it white and bare.  They also require good water quality in respect to temperature, salinity, and other factors.  Always be sure of the urchins’ specific requirements and adult size before purchasing.  Whether you have a reef tank or not, urchins can make very interesting additions to the aquarium.