Milky cloudy pool (with actual values!)

[Matthew]

Hi!

My pool is slowly becoming a big bowl of milk. I now barely can see the bottom of it. When i do backwashes, the little glass cup gets REALLY white, almost like white paint. Sand is brand new by the way.
Here are the values I have with me right now:

Everything related to chlorine: 0
CYA : 0
TA: 100
Chl Free: 0
p.h. : 7.6

This test was done at noon. Early this morning, the chlorine level was high, REALLY high (I put quite a lot of granular chlorine last night). What is my problem? Can't stand that white pool anymore.

Thanks!

[Guest]

Other info: About 20,000 gallons, inground. Heated but no water going through the heater now and since a while.

[Backglass]

First you need some CYA (Stabilizer). This is why your chlorine goes to zero in a matter of hours, thanks to the sun. You need to shoot for around 30.

Then you need to get your pool to stay at shock level for at least 24 hours...leave the filter running 24/7.

You didn't post your pools water hardness. Do you know it? If it is way off it could cause cloudiness.

[Guest]

Hi,

Water Hardness was 250 but I have put a product (recommended by pool store) that was supposed to lower it (the product contains phosphonic acid if it can help).

So, for 20,000 gallons how much stabilizer how should put once the water hardness is correct?

Big thanks for your time!

[Backglass]

Hi,

Water Hardness was 250 but I have put a product (recommended by pool store) that was supposed to lower it (the product contains phosphonic acid if it can help).

So, for 20,000 gallons how much stabilizer how should put once the water hardness is correct?

Big thanks for your time!

According to Bleachcalc (a GREAT program available HERE), you would need to add 4 pounds 12 ounces to a 20,000 gallon pool to take your CYA from 0 to 30. Get a 4-pound bucket and put as much as possible into a gym sock and knot the end. Then tie this on a string near your return outlet. The reason is that CYA granules dissolve very slowly. It will take 3-4 days for it all to dissolve. If you put in in your skimmer, it will just settle in your filter and get backwashed out. Test before adding the rest to make sure you don't overshoot.

As for your hardness, for an in-ground pool 200 is OK! The optimum number thrown around is 250-350. You don't want it to go any lower.