You guys are absolutely RIGHT ON that the water chem plugging up my sand filter! I took this morning off playing with the pump in various modes; recirculate, backwash, rinse, and filter. It's the dirtiest water coming out that I've ever seen. The pump has good flow running right and the pool water is less green but has a long way to go after adding 1 gallon of bleach, and 4 cups of dichloro on the first night, and half gallon of bleach on 2nd night.
I ran out of agent to meas the water chlorine and free chlorine. I need to buy them and bleach tonight after work.

I also noticed that the copper ionization block is surrounded by algae!
Is it necessary to turn pump off, remove and clean the copper block?
Should I replace the sand?