Algae coated Japanese Trapdoor Snails

[altwitch]

Hey all,

I've been an active aquarist for about 3 years now and in that time have had alot of different snails (both invited and unwelcome) and have never had this type of problem before. My crew of Japanese Trapdoors start out clean as a whistle but as they reach maturity start to collect a light greenish coating on their shells. It's unsightly, sure, but in addition I worry if it's detrimental to them and wonder what causes it.

Does this stuff hurt the little guys?
Is there a way to get rid of it?

Thanks for your help in advance,
altwitch

 

[wateriswet]

I don't think it's harmful. I used to have that happen to my yellow mystery snails shell but then I added neocardinia shrimp and a smaller nerite snail to the tank and they take care of it. It is very cute to see the shrimp or smaller snail hitchhike around on the back of the bigger snail as they graze off of the algae there.