The common plecostamus, or common pleco, is sold throughout the United States for anywhere from $3-$15 each as a good algae eater for the home freshwater aquarium. The appeal of common plecos to many people, other than their price, is that they can be kept in either a tropical or cold water tank and many larger ones even do well in horse troughs and outdoor ponds. Most common plecos are sold when they're around 3-5" long.

The most common mistake by far with the common pleco is not recognizing how large they get and how fast. The prevalent myth that fish grow to the size of their tank has crippled the welfare of many larger types of fish even when the buyer does know their natural adult size, so many of these fish go to homes that are way too small for them. Common plecos generally reach an adult size of about 8-12", though they can get larger than that. They reach their adult size slowly, sometimes taking up to two years to reach it depending on how much space and the quality of their food, but anyone who insists on keeping them in too-small housing will see an increase in uprooted plants, overturned or broken decorations and even disappearing fish.

The common pleco is a type of catfish and is a "slime sucker", he will try to "clean" his tank mates if given a chance. This means that larger, slow-moving fish with thick slime coats should never be kept with a common pleco as the latter may accidentally kill the fish. Namely, they should never be kept with goldfish of any kind and they have been known to cause problems with Angelfish, Oscars, Silver Dollars and more.

Next, since these fish are marketed as an algae eater many people get the false impression that algae is all they need. On the contrary, common plecos are voracious eaters and need quite a variety of food in adequate quantities to stay healthy. Aside from tank algae you can also feed your common pleco algae wafers, zucchini, cucumber, peas, melon and virtually any other type of semi-soft fruit or vegetable you can think of as well as shrimp, shrimp pellets and flake fish food. Bear in mind that juveniles eat a lot because they're growing and adults will eat a lot because they're a pretty large fish.

If you're planning on adding a common pleco to your home aquarium, make sure that you have at least a 55G tank with large open spaces on the bottom that will allow the pleco to move freely without destroying anything. As the fish matures, it may grow out of this tank size but 55G is a good starting size. Be sure to feed them a variety of food and, especially if it has tank mates that are aggressive eaters, make sure that it's sinking food of some kind.

You may be thinking that this sounds like an awful lot of space and work just for an algae eater and you'd be right. If all you want for your aquarium is something that'll suck up algae and make itself scarce the rest of the time, consider some smaller types of plecos, otocinclus or algae nibblers such as platies, juvenile apple snails and gouramis.