By Richard Lunsford, Kent Hunsuckle & Rone Fong.

Note: To provide a lot of info. concisely, I relied heavily on hyper-links to resources elsewhere on the Net. You can read the article & use hyperlinks to further explore the topics you need to know more about.

List of Prospective Algae Eaters.

1.)    Plecostomus a.k.a. ‘pleco.s’ or ‘pl*co.s.’ A large group of sucker-mouthed armored catfish from South America. They do not all eat algae (i.e.: the Zebra pleco.) but many do to varying degrees (some species, like the Zebra pleco., are carnivorous). The different species range widely in size and coloration. Due to release into the wild some have become established in Florida, where you can actually bow-hunt & eat them. Those well-suited for eating algae clean green algae off glass & fairly flat surfaces & driftwood; they are too heavy-bodied to clean small leaves on plants. They produce a lot of long ropey feces. May occasionally feed on aquatic plants but this is usually not troublesome. In rare instances may be dangerous to turtles but this is very unusual. Many people believe they need wood to rasp on, so include some real driftwood in the tank. Pleco.s will not eat all algae species or all the algae in the tank, and will starve to death if not given supplemental feeding (algae wafers or flakes, Zucchini, etc…). There is a myth that if you spell out ‘pleco.’ yours will die shortly, & some people think this is cute or true so on fish forums people often write ‘pl*co’ (I think this is idiotic). Some recommend you get a pleco. roughly your turtle’s size or a bit larger; this may discourage turtles from attacking it.

a.)    Common pleco. – actually a few species are sold under this name. Tend to be hardy algae eaters and may hit 18 inches in length, give or take. They are heavy-bodied & outgrow almost any tank under 120 gallons.  The best plan is to use one a few years, then trade it in at the pet store. Widely available in pet stores, Wal-mart, etc… Mine has become less shy with increased size. Considered excellent algae eaters.

b.)    Bristlenose Pleco. – Resemble the common pleco. but have a number of thorn-like whiskers growing from the nose, larger in males, and usually only get 5-6 inches, but remain heavy-bodied & adults shouldn’t be kept in tanks under 20 gallons. Males are territorial. This is one of the pleco. species fairly easy to breed (except in turtle tanks), and the male guards the orange eggs. Mine is shy & stays hidden in a synthetic log most of the day. Sold in a minority of pet stores but can be found. Widely lauded as a great algae eater. Read a Discussion by Some Owners.

c.)    Clown Pleco. – more than one closely related species may be sold by this name. Reach 3-5 inches & are much smaller than bristlenose pleco.s. Quite pretty when visible. In my experience, they are very shy & can disappear into the tank without being seen for days. Sold in a minority of pet stores but can be found. They will also be outgrown by any turtle species, which is a drawback. Reports of their algae-eating acumen range from ‘great’ to ‘eats a little;’ not universally lauded enough to whole-heartedly recommend.

2.)    Chinese Algae Eater (Gyrinocheilus aymonieri) – A vaguely loach-looking bottom-feeder from Northern India and Thailand (not China) that can reach 11 inches in length but very rarely gets that large in our aquariums; 4 to 6 inches is more typical, & they are nowhere near as massive as pleco.s of similar length. They have small sucker mouths. They tend to be rather skittish & fast, darting about the tank when spooked & can avoid turtles pretty well. They are territorial & will scuffle. The fish hobby has a love/hate relationship with these chaps. The young are generally considered excellent algae eaters, but older ones vary (some do well, some do not) & may turn to eating the slime-coating off other fish, particularly large, slow ones. There are reports of CAE’s literally sucking a chunk of meat out of other fish & injuring or killing them, though this seems fairly rare (some may be unusually aggressive). I’ve never heard of one attacking a turtle, although I’ve often watched them buff my turtles’ shells (which tend to be algae-free). I read in one post that they’re fairly intelligent (for fish).

3.)    Otocinclus (Otocinclus affinis) – another South American sucker-mouthed catfish but much smaller & softer than pleco.s; some report prone to mysteriously die shorter after purchase but if they live the first few days they tend to survive long-term & (if not eaten). Fairly sedentary & not all that wary; can be caught by vigorous hunters & are edible. Not a good choice for known fish-aggressive turtles; may work with more docile individuals in large tanks with lots of space & cover. Be wary during water changes; one of mine became bubble-encrusted which immobilized it & my Southern Painted ate it. Excellent algae eaters within their size constraints, and are small enough to clean algae off small surface like leaves that a large pleco. can’t work on.

4.)    American Flag Fish (Jordanella floridae) – a U.S. native from Florida, hardy & renowned for eating filamentous (green hairy) algae. Males get up to 3” (I’ve seen none over 2”) & females slightly smaller. It’s a type of killifish and growing in popularity. An egg-layer & reportedly fairly easy to breed (one article discussing that). Males have a subtle but striking American Flag-like coloration; these fish resemble small jewel cichlids or slightly elongated sunfish. My Southern Painted initially pursued them vigorously until she got used to them. Historically hard to find but have been making headway into more pet stores. Great for cleaning up filamentous algae (including off plant leaves) but don’t have sucker mouths so don’t expect them to ‘Hoover’ the green film off glass surfaces. The cited article mentions them eating beard algae.

5.)    Butterfly Goodeid (Ameca splendens) – a platy-sized fish famous for algae-eating but very hard to find. It’s a live-bearer & said to be very hardy. Reportedly eats hair algae (read this testimonial), green spot algae and even blue-green algae (which would be a major vote in their favor; few creatures will. Read this personal testimonial). One claim that’s hard to believe but possible is that they eat the dreaded black brush algae (read this testimonial.) It’s noted they can become aggressive toward other fish & softer plants, although how common this is isn’t clear (read this testimonial.) Read an article of peoples’ first hand information at The Krib. If what people say is true they are excellent algae eaters & if I run across’em in a pet store I plan to buy some (although the reported aggression toward other fish is a concern). I believe they’re hard to find.

6.)    Rosy Barbs (Barbus conchonius)– Beautiful solid-built medium-sized fish from India. Reputedly can reach 6” in length but in captive tanks seem to top out around 3”. Males are more richly colored & while some say this is seasonal, the ones I kept stayed that way. Due to the sexual dimorphism, you can keep one gender & avoid breeding. Vigorous, active & fun to watch but will attack & kill ghost shrimp. See Robyn’s Rosy Barb Page. One thing; they definitely have the ‘tropical fish’ look & your tank won’t look ‘natural’ with them in it.

7.)    Siamese algae eaters (Crossocheilus siamensis) – A famous but often hard-to-find fish from Thailand and the Malay peninsula legendary for eating the dreaded black brush (‘beard’) algae (red algae). You can read this excellent article on Siamese algae eaters, False Siamese algae eaters, Flying Fox & Chinese algae eaters. The first 3 are very similar-looking so don’t trust your pet store’s listing of ‘Siamese algae eater;’ check & be certain.

8.)    Flying Fox (Epalzeorhynchus kalopterus) – This article states they’re aggressive toward their own kind & recommends sticking to one per tank. Strangely much easier to find in pet stores than the Siamese algae eater.

9.)    False Siamese algae eaters – Exactly what species this is isn’t clear, but read the article on how to tell them from Siamese algae eaters. This article says false SAE’s are more aggressive toward each others (recommends one to a tank) & more demanding of water quality than SAE’s.

10.)                        Live-Bearer Fish – Many commercially available tropical fish like guppies, swordtails and mollies will eat hair algae. Mollies tend to like brackish water (tip for you diamondback terrapin owners who keep brackish tanks). Be aware live-bearers can breed successfully enough to overpopulate the tank; many (guppies) are hard for turtles to catch so you may need to dip-net & kill them occasionally to thin the herd. I wouldn’t recommend them for primary control of hair algae or for cleaning green film off glass, driftwood, etc…

11.)                        Snails – The most common varieties sold seem to be the Apple snail & the Mystery snail (really just another type of apple snail). Some apple snails species get very large (allegedly softball-sized; I’ll believe it when I see it) whereas mystery snails stay smaller. Those of use breeding snails for turtle food often turn to the Columbian Ramshorn snail (not to be mistaken for the Red Ramshorn snail, a different genus; the Columbian has a rep. for eating live plants, whereas the smaller ramshorns don’t). Overall, snails eat some algae but don’t have the rep. pleco.s, CAE’s & Oto.s do for cleaning the tank. Some munch on plants, too. They’re an interesting addition to the tank, but I wouldn’t rely on them for primary algae control.

12.)                        Algae Eating Shrimp – a number of shrimp eat algae but the Amano shrimp (Caridina Japonica) from Japan is one of the most famous. Yes, they eat algae but I wouldn’t expect my tank ‘spit-shined’ by AES alone. In most turtle tanks, they’ll be killed. They are generally much harder to find than ghost shrimp & more expensive; this is not a cost-effective algae control measure for most tanks. Read more in The Krib’s Shrimp Article and the Robyn’s Shrimp Species Page.

13.)                        Ghost Shrimp – Partially transparent shrimp about 1.5” sold as feeders at about 4 for $1 (I’ve seen’em sold as pets for $1.50 apiece; buyer beware). A web search on ‘ghost shrimp’ will turn up a number of shrimp species, but you’re after those in the genus Palaeomonetes. They are omnivores & pull janitorial duty in the tank; that includes eating some algae, although they aren’t a good choice for primary algae reduction. They will be eaten eventually. Aggressive fish like rosy barbs will mangle them. Fairly common in pet stores. Read more in The Krib’s Shrimp Article and Robyn’s Shrimp Species Page (which even discusses breeding experiences with them!).


Online Resources:

1.)    The Robyn’s Series of online web pages covers an amazing array of topics, and several of those pages are of interest to turtle keepers. Check these relevant articles out:

a.       Robyn’s Aquarium Algae Page.

b.      Robyn’s Common Plecostomus Page.

c.       Robyn’s Bristlenose Plecostomus Page.

d.      Robyn’s Otocinclus Page.

e.       Robyn’s Rosy Barb Page. (Note: my males were way more colorful than what she pictured).

f.        Robyn’s Algae Eater Page (Siamese, False Siamese, Flying Fox & Chinese Algae Eaters).

g.       Robyn’s Snail Species Page.

h.       Robyn’s Shrimp Species Page.

i.         Robyn’s Algae-Eating Animals Comparison Table.

2.)    The Krib – a great place to read up on plants, algae and related matters.

3.)    Planet Catfish – Pleco.s & Oto.s are catfish, and you can learn a lot about a staggering array of catfish species at this site.

4.)    Article on Ramshorn Snails.

5.)    Article on Columbian Ramshorn Snails.

6.)    Article on Introduced Pleco.s in Florida.