I'm getting a lil frustrated and this is mind boggling...three times over the last three weeks now I've bought a cuc package, and each time, the snails seem to become paralyzed immediately and eventually die. I've spent approx $150 bucks on snails and crabs lately and only a few reef hermit crabs are surviving. I don't understand because my fish are doing very well and happy, my corals are fully open, including great polyp extension from the sps' corals. No nitrates, nitrates, 78° temp, undetectable phos, 400 cal and 8 alk, 1.025 salinity. I also don't feel any current in the tank and have unplugged everything for a few hrs to make sure. So I'm really confused on what's going on with my tank that's killing all inverts. The only thing I can think of is my mag being high from me dosing Kent M magnesium, but I've stopped now...the mag just tested at 2430 ppm.