Pool Chemistry way off

[Karthas]

We just got back to Tucson after 2 months and our pool chemistry is a disaster. We had someone come once a week to clean and test the pool. Our floating tab holder had 4 tabs in it and the skimmer had 4 tabs as well. I immediately removed all the tabs. I only use Liquid Chlorine except in the summer when I also have 1 tab in the floater. Here are the test results:
FC 36
CC 0
PH above 8.2
TA 40-50 and yellow
CH 700
CYA 100
Temp 50
Please tell me where to start. Thank you in advance for your expert recommendations.

 

[mknauss]

I suspect your pH is not that high with the lower TA and the fact that the pH test is effected by high FC. So do NOT adjust the pH right now.
Do a dilute CYA test. 1 part pool water, 1 part tap water. Use that for your sample and run the test again. If you get 50 or higher it is likely best to drain 25-50% of the pool water. Otherwise you likely can let the CYA come down over winter, drain a bit of water if you are going to get some rain, etc.

 

[JoyfulNoise]

Take all chlorine sources out for now and let the FC come down to normal. Your pH test is being skewed by the high FC and that’s also causing your TA test to turn yellow instead of red.

If you have distilled water around, you can do a 1:1 dilution of pool water and DI water to cut the FC in half without affecting pH. But even at 36ppm FC, you’re still too high to test pH reliably.

 

[Karthas]

Thank you. My CYA level was 60 before we left town. I will retest the CYA level. Do I need to do anything about the TA level or is it ok?
I retested the CYA level using the diluted pool water and distilled water and the CYA level is 140. I doubt we will be getting any rain, so we are going to drain some of the water and refill to lower CYA.

 

[mknauss]

If you discontinue the tablets, the TA is fine. As you add fill water the TA will rise.

 

[Karthas]

Thank you. I appreciate all the information from everyone. I found TFP 4 years ago and have learned a lot about caring for our pool. Now I only have problems when I have had other people take care of the pool. I only use tablets with the liquid chlorine in the heat of the summer as the chlorine level drops quickly with the sun on the pool all day.

 

[JoyfulNoise]

Thank you. I appreciate all the information from everyone. I found TFP 4 years ago and have learned a lot about caring for our pool. Now I only have problems when I have had other people take care of the pool. I only use tablets with the liquid chlorine in the heat of the summer as the chlorine level drops quickly with the sun on the pool all day.

Salt water chlorine generators work well here in the desert. A properly sized unit will maintain steady FC levels all throughout the heat of the summer. I’ve had an SWG since we built our pool back in 2013 and I’d sooner fill my pool in with dirt than operate it without an SWG. I use maybe 1-2 gallons of LC per year (in the winter months when the water is too cold for an SWG) and I have had the same 8lbs bucket of tablets for the last two seasons (I’ll use one or two tablets if my CYA is low).

 

[PoolStored]

Now I only have problems when I have had other people take care of the pool. I only use tablets with the liquid chlorine in the heat of the summer as the chlorine level drops quickly with the sun on the pool all day.

I second the notion. Get an SWG.