help fish start dying

[Megalodon]

I actually had one of those pink filter-feeding cukes until recently. It was withering away and shrinking as it wasn't getting enough food. It never stressed and expelled it guts but I didn't want to take any chances and just flushed the damned thing. And you know what? My tank has been doing better ever since. IMO just avoid those things entirely. I've noticed J&L Aquatics doesn't sell them anymore. It was pretty while it lasted, though.