Nerites

I thought nerite snails only bred in brackish water? I'm a little suprised to find eggs laid on some of the stones and the log in Franks tank

Nerites do lay eggs in fresh water, they look like sesame seeds. But they don't hatch. I've tried scraping them off but they are stuck pretty tight, and I was damaging the surface of the wood so I gave up. I find they like wood in particular as an egg laying site, but they are also on my filter bracket and plastic ornaments.

In my experience, nerite eggs are solid white while cory eggs are a bit translucent - or at least the fertile ones are. Infertile cory eggs are also solid white.

I put the 4 nerites into the big tank and I cant believe how much brown algae they've eaten!! I'm very glad I ordered a few more and now I know why I never had to clean the glass in his tank! I'm hoping once they've cleared the algae from the glass and stones they'll crack on and clean the plants up a bit for me. So far the assassins have left them well alone.

ps: they do poop a lot ...usually the corys disturb the sand enough to hide most of the fish poo, they can't keep up with the nerite poop though 

I'll supplement their diet with algae wafers, blanched courgettes, blanched spinach or blanched lettuce when they finish with the algae and I've got 3 tanks to put them in. I'm not sure putting them in with the puffers would be a good idea as they're a bit nippy.

BTW I just found a kamikaze nerite cleaning an assassin snail