I decided to restart one of my old tanks, and the moment I switched on the pump, this huge amount of dirt and rotten egg smelling water came out from the return pump. It was strange because I never knew there was residue water left in the pump! Same goes for the chiller. Any advice on how to prevent this from happening?
I am planning to use aeration to remove the hydrogen sulphide, but are there other aquarium products that are good?