Well a good few months ago I started a tank, cycled with TSS and bought a betta and two nerite snails. Well around two weeks ago one of the snails (Boris for anyone who is interested) died, as when I picked him up to check on him he totally disintegrated, leaving an empty shell in my hand... Well yesterday I concluded the other snail (Brian) had sadly passed on too... He was still in his shell but smelt really bad and wouldn't retract if I touched his foot. So I was wondering, what killed them? Details on the tank below: 2.5-ish gallon no plants Ammonia-0 Nitrite-0 Nitrate-10 (due a water change tomorrow) Sadly these results were only today's not when either snail died First snail death: Ammonia-0 Nitrite-0 Nitrate-0 (straight after water change) I have been using prime with a weekly 30-50% water change Any help would be much appreciated, the snails are missed a lot and there is concern over Sus the Betta's safety Thanks!