Okay I moved into this house a few months back and I have been using some of the Aqua Chem test strips and then buying the items it says. I have a chrlorine feeder that holds about 10 of the 3 inch chlorine tablets and I have been cleaning out the baskets and I did my first DE filter flush/replenish a few weeks ago. I have below water scrubbers that when the pump is going (I have it running for 5 hours a day) it moves all the around to the traps.
So far I have only had to shock the pool once and this was after the pool was accidentally turned off my my wife playing with knobs.
When we bought the house the pool was blue all the way to the bottom blue pebbles. Now the water is clear but I am seeing small patches of a yellowish/brownish color that seems to be ON the bottom of the pool (not in the water) right now its only covering about 1/4th the pool but its not "clean" all around like it was when we bought it.
The numbers from the tester I used is -
Free CL 0.8
CYA 250 (this number has always been red/which I suppose means bad) but there is no indicated on how to change this number.
Am I doing something as stupid as not using a scrub brush on the bottom like I should or something? Like I said I never owned a pool so unsure how to do things outside of the filter maintenance, and the chemical maintenance.