What is eating my shock???

[Ohioman]

I live in Ohio, have a 20 x 40 in ground pool and have never had any problems before...until this year.

I took the cover off on Friday and found Brownish/Green water and could not see the bottom of the deep end. I vacuumed and discovered my normal yearly bunch of worms...1000's of them. After vacuuming, I did all of my chemicals in the same order as always...sodium bi-card, chlorine and shock. The next day the water turned mostly blue, with a little brown in the deep end...but still very cloudy. I used Super Floc on Monday and cleaned it out on Tuesday. This seemed to work because I could see the bottom now, the pool is blue, but still a little cloudy.

To make a long story short...in the last 2 days I have put 10 more bags of shock in the pool, but my free chlorine level is still ZERO. What can be causing this to happen? My PH is good and total alkalinity is just a little high. I am stumped. Any thoughts would be greatly appreciated.

[Guest]

Have your pool water tested for the presence of stabilizer (cyanuric acid). Without 30-50 ppm, unstabilized chlorine will dissipate as fast as you can add it.

[dogette]

From what I've been told high Phosphate will add to your problem along with low cyanuric acid. Most pool store do not check for phosphate issues regularly. Maybe ask to have your phosphate checked next time you having you water checked.

[KC1]

IF CYA IS TO HIGH LIKE MIN IS AT 150. THE CHLORIEN IS LOCKED