At the end of a long day, I got a call to go and look at this beauty. I have used alum a couple of times in the past, but I hate the way it gums up the cartridge filters here in Florida because you never get it all out. I can't get alum now anyway but there's a box of HTC green to clean floc lying around if I care to use it. I have a portable filtration system that I can take the cartridge out of and just vac to waste. Replacing water or draining is not an option I really want to go to in this case as the house is on well water and I would not like to be responsible for burning out the well pump. Is a slam a viable option while washing the filter every day? I put 3 gallons of chlorine in and half a gallon of acid, I took out the filter and left the whole thing running. I will return tomorrow.