Ditch feeder blocks entirely. they are death. fish are better off hungry when you leave, than poisoned in putrid water.......................................................... left for five days but tetra died when was gone and decomposed and got somewat eaten plus there was feeder block in tank so I removed block but I believe that is wat cuased outbreak both deseased fish I had in tank one withpopeye other with fin rot died last night.................................
Many many years ago I put a small one in a tank before leaving for surgery (lfs sold me on it).
came home a week later to the most disgusting tank of death I ever had in my life.