New to BBB Method ... 100 CYA

[tabjraxa]

Hi,

About 2 weeks ago I had what I assume was an algae bloom -- cloudy white pool.

After trying to cure this with granular pool shock from Leslies, I took the Pool Water in to be tested ... they said ...

TC = .5
FC = .5
Alka ... was normal (don't remember the numbers)
Phosphates = 2500 (I chose to ignore this for now)
PH = 7.2
6,000, Fiberglass Pool

So, I came back to this forum after a long abscence ... read the BBB method, and went to work on the recommended shock levels for the amount of CYA I have in my pool -- if I read correctly 25ppm.

After about 3 doses of the above 25ppm (2.5 gallons of 6%, according to the BleachCalculator) I think it is clearing up.

My questions are ...

Should I do something about the 2500 level of phosphates?

And, should I do something about the 100 level of CYA?

Thanks,
T.

[JohnT]

Your main cause for concern is the CYA. You'd have an easier time managing the water if you got it down below 60ppm, and preferably even lower. Unfortunately, the only reasonable way to do that is to replace part of the water. TDS is largely a bogus measurement, but you will reduce it when you replace the water unless your tap water is high in TDS as well.

[CarlD]

Did I miss something? The OP didn't mention TDS, just phosphates. (But I agree: In 99.99% of situations, TDS is irrelevant--once in 10,000 times it's the problem).

The answer is: If you can clean up and maintain your pool then, by definition you don't need to worry about phosphates.

Now I have another question: Is your CYA 25 or is it 100ppm?

If it's 100ppm, you CAN maintain it and swim safely if you keep your FC between 8 and 15ppm--just don't let anyone wear new, designer bathing suits. Otherwise you are fine. I don't like it that high, but I disagree with JohnT that you need to be below 60ppm. aylad maintains her pool consistently at a CYA of 80ppm because chlorine burns off too fast in Louisiana. I personally keep mine between 30 and 50, but if it gets to 60 I merely compensate with my FC level.

The shock level for CYA=100pp is 25ppm of FC--maybe that's what you meant. You'll need to keep the pool there until it's clear. Then maintain it at the 8-15 ppm level.

Or you can drain 50% of the water and refill for a CYA=50.

Where I am, it's not much of an issue as it's been raining all week and a lot of water is coming in and draining off--maybe if it stops pouring tomorrow I can take a proper "snapshot".