No chlorine

DSdiver · May 29, 2014

Hi, we have a 33,000 gallon SW pool with a vinyl liner and auto cover, it was built two years ago. We opened the pool two weeks ago, the water had been crystal clear until today. Last night the free chlorine was between 1-2 and pH was 7.5. Today I opened the auto cover and the water was super cloudy-when I checked the chlorine it was zero. I then did my weekly chemical check use the Carefree pool kit with the following results:
No color change with the chlorine test
Salt 3400
TA 160
PH 7.2
CYA 50
I was told by the pool builder that I didn't need to add stabilizer when they opened the pool. We had difficulty keeping chlorine in the pool last summer too, at that time when they tested for CYA it was almost zero so we added it.
I now have the system set to super chlorinate for 24 hrs.
My questions are:
1. Should I be "losing" CYA? (I haven't add much water at all)
2. Should I treat with liquid bleach since I'm super chlorinating?
3. What is causing the chlorine loss? (I super chlorinated after a heavy bather load on Monday so I just don't get it!)

jmbradwell · May 29, 2014

1. Get some chlorine in the pool!! Don't try to use the SWG exclusively for getting your chlorine up. They can keep up with your daily loss but have a hard time getting your level up.
2. What is your CC level?

UN1017 · May 29, 2014

DSdiver said:
1. Should I be "losing" CYA? (I haven't add much water at all)
2. Should I treat with liquid bleach since I'm super chlorinating?
3. What is causing the chlorine loss? (I super chlorinated after a heavy bather load on Monday so I just don't get it!)

1. What was your CYA at before it dropped to 50? It can be lost over the winter but not for all pools.
2. Bleach is pretty much the only way to "super chlorinate". Actually you need to follow the SLAM process. SWGs cannot make chlorine fast enough for super chlorinating.
3. Something is growing in your pool. e.g. algae (or you may have an ammonia issue)

It looks like you have a TF-100, right?

Divin Dave · May 29, 2014

This is why TFPC recommends minimally checking FC every day. It only takes a very short time to go from Clear to Cloudy to worse.

I googles the Carefree Kit you have. It does seem to be drop based kit, but couldnt find very much detailed about it.
In any case, the problem is that you seem to have been keeping your FC level too low.
With a FC of 1 or 2, with little or no CYA, it will quickly bet burned off
If you had 1-2 with a CYA of 50, that is way too low any how.

Here are the TFPC recommended levels. If you follow these recommendations and have a recommended test kit, then cloudy water is easily avoidable.
http://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock

It sounds as if you will need to SLAM the pool. Unfortunately, your Carefree test kit is not equipped with the proper tests to perform the slam. Highly suggest to aquire one asap before you end up with a way worse situation.
you can order a recommended test kit, at www.tftestkits.net as a FYI, the Taylor test kit will not have enough FAS-DPD regents to complete the SLAM process. Given your situation, you should choose the TF100 kit with the XL option.

JasonLion · May 29, 2014

Sunlight breaks down chlorine. People swimming use up chlorine. Chlorine breaks down very slowly on it's own, but faster at higher temperatures (generally at 90+ degrees).

DSdiver · May 30, 2014

We have a TFT-100 test kit with the xl option just bought it a few weeks ago

DSdiver · May 30, 2014

Dave,
We do have TF100 kit with the FAS-DPD and we got the extra large so I'm hoping we are good on that right now. I have a full 3 day weekend of 12 hour shifts starting today is there anything I can do tonight after my shift quickly. to at least not make the pool worse until we can slam it.

JesseWV · May 30, 2014

Using PoolMath with 33,000 gal and CYA 50:

It's going to take 10 jugs of 8.25% bleach to get you above shock level (20) and probably a few more to maintain it through the SLAM process. Adding less than that is probably going to waste it.

If you have limited time, I would recommend adding 12 jugs just after sunset with the pump running continuously. This would get you up to Mustard shock level, which is a little higher than normal shock but will be more forgiving if you have less opportunity to test and redose.

The chlorine will be used up pretty quick so you'll need to retest FC and CC as soon as possible and add more bleach to get back above 20.

The process repeats until the water is clear, you have 0.5 or less CC, and you lose no more than 1 ppm FC overnight.