the first ones i didn't know i had them, they just came out of hiding, around 1cm and were working on a hikari bottom feeder wafer, i saw something moving but couldn't tell what it was and then i saw the rest of it i couldn't believe it and the next batch showed up a few weeks later and haven't stoped, they just eat flakes that fall to the bottom when i feed the rest of the fish, and then the algea wafers, i have really dense plants with moss growing through it also they like it.