New Fish Dies in established tank.

Hi Thor,

Thanks for all the inputs.  As far as acclimation is concerned, I usually let the bag float in the tank for around 20 minutes. And then put the fish in the tank along with the water in the plastic bag.

As you said, I will try to keep the tank running till I add new fish. I will do a vacuuming of the gravel and replace the tank with a 90% water change before looking to add fish to it.

Can you suggest what fish can be added to the tank.