HELP-pool keeps getting worse

[Specialkman]

I've cared for my pools for 20 years and have never had this kind of a problem.

Pool is 33,000 gallons
Chlorine is 10+
PH is 7.2
Alkalinity is 110
My stabilizer and solids are fine-tested at pool store.

I've tried algaecide, shock treatments, etc. and the stuff almost seems to thrive on it. I've never tried bleach. Is that something that might work? How much bleach would I need? My chlorine levels have been over 5+ for 3 weeks and yet there is no reduction in algae. Now I can't even see the bottom of the pool. My PH was 7.6 but it's been lowered because of added acid to get the alkalinity in line. What should I do?

[CarlD]

OK:
1) No matter what the pool store says we'll need to know the CYA level. It directly affects what we can advise you to do. You need a 15ppm of Free Chlorine if your CYA is 30ppm, but you need 25 or 30ppm if your CYA is over 100ppm.

2) Is your pool vinyl-lined or concrete/plaster/tiled? This too is important.

3) You will need a test kit that measure chlorine to very high levels. This is called a FAS-DPD chlorine test (a DPD test is NOT the same thing). You can get this test at Leslie's, sometimes, or in the PoolSolutions test kit. Since you need it RIGHT NOW, Leslie's has a FAS-DPD test in one kit available at their website. The whole kit is about $65+ shipping. I haven't tried it, but it uses the standard Taylor FAS-DPD test, so the rest is probably OK.

Meantime, you want to get your pool up to about 15ppm, just to start. You'll need to add 3 gallons of 6% bleach to do that--4 3qt containers. You'll need to check your water and add bleach as needed 3x /day.

You can use MWSmith2's free bleach calculator, or you can figure that 1 gallon of 6% bleach adds 6ppm of chlorine to 10,000 gallons of water. 1 gallon of regular, 5.25% bleach adds 5.25ppm to 10,000 gallons. Figure accordingly for your 33,000 gallons.

or

(1,000,000/33,000) * .06 * gallons of bleach = added Free Chlorine in ppm.