I had 3 of these snails and then they gradually disappeared and died off. My last one just died this week and had grown quite big. My tank is 75gal FOWLR. I have about 90 lbs of LS and the same LR. 5 fish altogether, 2 clowns, 1 Yellowtail Damsel, 1 Yellow Tang and 1 Coral Beauty Angel. Anyone out there have any ideas? I do a 10 gal water change about every week so I can't believe its my water.