If you want fish to eat algae *and* scavenge leftoversfrom the substrate (and most of us do need both those jobs done), then often you're looking at two different fish to do them. I don't know a single fish I'd say in good conscience is a good algae eater and a good scavenger.
Cory cats are excellent scavengers, as are most loaches. They will pick the uneaten food and such from your substrate and help out there. Neither corys nor loaches will eat algae to amount to a hill of beans (as far as I know). Both corys and loaches prefer to be in shoals of four or five, if at all possible. They don't do so well in ones or twos. To my knowledge, pretty much all corys are peaceful and will not antagonize other fish; some loaches are great in communities, but some species can be problematic. Some species of loach have fantastic personalities, though, and are incredibly entertaining to watch. Do your homework if your considering a loach.
Ottocinclus cats are very industrious algae eaters, and so are Siamensis algae eaters (SAE's, aka Siamese algae eaters). Neither can be relied upon to scavenge food from your substrate though. True SAE's are maybe the most effective algae eaters, but they are difficult to find and identify. Often fish shops will mistakenly sell imposter fish as SAEs (e.g. False Siamensis and Flying Foxes). IMHO, stay far away from the Chinese algae eater - as it gets older it gets aggressive with other fishes and eats little or no algae. Unfortunately, the CAE is what is seen by far most often in fish shops (at least around here), often labelled generically as 'algae eaters'. CAE's are very quick fish and can aggravate your other fish very, very much if they've a mind to.
Plecos are a mixed bag. Some species of pleco eat tons of algae. Some eat very little. Some will scavenge for uneaten food on bottom, but IMHO they aren't terribly effective at it. Try to be as educated as you can about the particular species of pleco you're buying, so you know what to expect from it. Not all plecos are good algae eaters. Also, please don't buy a pleco unless you know you have sufficent tank size and filtration to keep it. Most species of pleco will reach 10 to 18 inches in adulthood. There are some that stay smaller, but it's generally a little more work to find those.
pendragon!
i was thinking of gettin a clown pleco,apparently they are quite small and easy to keep but corydoras look so sweet!I dont know what to choose,i basically need something that'll eat most types of algae , and thats eat my plants and left overs.Oh i forgot to say that i recently medicated my tank for fin rot(about four days ago)so would it be wise buying anymore fish for it
i would recomend the pleco because they are very hardy and will most likly be unefected by the meds. Also theyll eat just about anything they could find.
