A lot of people catch crabs from the sea etc to put in there tank for food or life etc but has anyone had any problems with disease or parasites at all? Does anone dip things in any solution to attempt combat? Reason I ask is I have these little kinda white kinda worms but more like lichens about 2-3mm diameter growing on the glass and rocks, this has happened by one of a few possibilities:- 1 Introduced some shrimp and snails from the sea recently 2 Introduced new lump of cheatomorpha to fuge purchased on ebay 3 could of come out of rock or as a result of adding gravel (this is doubtful i think) I think it is most likley the first but cant be certain, need to test tank over weekend. Are you scared of disease to your octo (tank bread) being contamined by disease from crabs etc (from sea)??? Any thoughts anyone?