i think im thinking the same thing but i have tons of those in my tank i dont think there bad but they do mutiply fast mine i see most of mine at nite when the lights are off
haha not a prob, I liked piggy's description that the shell looks like a fingernail, thats pretty much right on. i've got them ranging from 1/8" long to almost 2" it seems. it's kinda hard to tell with a bowfront it can tend to magnify stuff sometimes.