Breeding Astrea Snails
 

Well it was never intentional, but apparently i'm breading snails now. At first I thought they were just little slugs, a type of hitchhiker, but I've started to find more and more of them. particularly in the PVC pipe I use to tie Nori to for the fish. I was going to take a picture of them, but when they are still developing their shell, they move into the rocks very fast. I'll try and post some pics if I can catch a glimpse of a juvi.

try googling stomatella snails - these are good hitchikers and may be what your are finding

Thanks! Those are them! Awesome.