So i bought 9 cardinal tetras from the LFS, sadly since having them one goes off alone and dies, i remove the dead body, another does the same. I am now down to 6 cardinals and 1 again is on its own. whats going on :( my params are fine
Do they show any other symptoms? If not, I would put this down to poor stock. Farmed cardinals from the Far East have become very weak and with no other obvious cause, general weakness is the most likely explanation for the deaths.
Just a note, but 28C is too warm for your other fish. The zebra danios do best between18- 24C, cherry barbs 20-26C and dwarf gourami 22-27C so I would set your temperature at 23-24C for those fish.