I am new to learning about pools and am trying to get the constant algae out of my pool. Last weak in trying to learn about my pool I found the PS website and learned just enough to be dangerous. My ph was 6.8 and my TA was about 60. My pool is about 20k gallons. Anyway, I started adding borax to get the ph up and kept watching the TA to make sure it was okay. After adding 16 lbs. of borax over a couple of days, the ph went to 7.2 and the TA to 80. I started using bleach and kept using the trichor tabs I already had.

After more reading, I realized my test kit was probably too old and did not have reliable readings. I got a new kit and tested to find the ph at 7.2, fc at .5, TC at 1.0, TA at 150, Calcium was over 500 (stopped adding drops thinking I was doing something wrong), and CYA is way high- not even close to the first mark.

I took the trichor tabs out and dumped in 5 lbs. of 55% chlorine shock. What should I do next? I figure I need to get the CYA level down and the CH down as well while keeping chlorine levels high to get rid of the algea (not sure about the stained walls)

I have a sand filter by the way which has low pressure and low flow. After reading on this site, I now think the impeller on the pump must have some blockage.

Thanks for your help,

Greg