Typically your okay if you keep softies with softies. The important thing is keeping softies and stonies in the right balance. If your losing new aquisitions frequently but have healthy established corals, its likely a sign of chemical warfare.
Here's to swimmin with bowlegged women.
Reef with 30G Sump/Fuge Combo
-30G LTAnemonarium with mated porcelain crabs, 10 sexy shrimp, and 2 pink skunks all tied into the other 135G in my system.