i know when i first started my 65 up, i had problems with snails. i found that i had a metal union above my pump in my tank that was rusty.. it was in my
sump, and always submerged in the water. until i put a light down there, i didnt notice it. but the rust was in my water for a long time. never could keep any snails alive, i tried 6 of them before i discovered the rusty piece. i replaced it with a
pvc piece and got a poly filter. the poly filter removed all of the bad elements in the water and now my snails are staying alive. do you have anything rusting in your tank anywhere? equipment or anything? i believe it disperses high amounts of iron into the tank.. which could possibly kill inverts. it killed sails, shrimp, crabs and a starfish on me. once i filtered it out, and it was all gone, i have had turbos, a starfish, horseshoe crab and hermit crabs in there.
just an option of what it could be.
