I'm not sure. If there's something in my feeding or other circumstances that's killing them, I might settle on another fish. If the last one hangs in there, then I'll be more likely to suspect they were sick coming in. I'll let you know
Sorry to hear about your Molly. I look at them in the
LFS and I do like them.
My personal favorites are the Dwarf Gourami (he lets me pet him) and the Ghost Shrimp.