This may not be the place for this post, but I felt that for the beginners out there like me, it was worth putting here.... I was at a Petco store today in Hamden, CT looking for some plants....I happened to overhear a woman ask the man working in the fish dept. if they had any algae eaters..... The man asked - "what size tank?" to which the woman replied "20 gallon......" He marched her right over to the Common Plecos and said - "This will do the job." Now I often resist butting in, but I couldn't help myself. I chimed in with the old, "Are you sure you want that fish? They will do a great job, but get very large and will outgrow that 20 gallon quickly if well fed......You might want to try one of these guys instead. They stay small and will do a great job keeping your tank clean".....and pointed to the tank of Otocinclus. To which fishman replied - "Those are catfish. She wanted an algae eater." I said "OK, they are catfish species, however they are algae eaters......some of the most efficient around and will fare better than a Common Pleco in that small tank. And even then they should really be in a larger tank which is why I only suggested one." Unfortunately, she bought the Common Pleco........ It just goes to show you that they may work there, but they don't necessarily know what they are talking about.