i was at work and my girlfriend calls me and says the anthias that i bought on saturday is being attacked by my nassius snail. she looked closer and he was trying to fight them off and by the time she moved the rock he was behind he had stopped moving and 4 snails were on him. well hes gone. now what do i do. a water change or let it be. she did get him out of the tank right as he died. a little help please. i checked my water on saturday and they all read 0. so i know my water is good.