Really high FC

[slangner]

Hi all,

I think this may be my first post! Our pool was just finished in July, and I have been trying to learn pool chemistry as fast as I can. My builder did not teach us much, so TFP has been a Godsend! I have been using the Pool Math app for about a month. I live north of Houston, and the weather has been chilly and overcast, so I haven't worried too much about pool chemistry, but as we start getting closer to pool season, I want to make sure the pool is ready, and I have learned enough to balance the water when I have swimmers in the water.

For the last couple of weeks, the free chlorine has been going up drastically. On 1/26, it was 8.0. The CYA was at 30, so we added 8 lbs of Dry Stabilizer (as Pool Math recommended). We also cleaned the filter and washed the SWCG (although there was no corrosion). We have needed to add some salt over the last few weeks and also added some Calcium Chloride two weeks ago when CH was 280. Water looks clear, but there does appear to be some very light dirty brown areas near the drain, that brushing doesn't seem to help.

Do I need to worry about the FC being that high? I am having my husband buy some Muriatic acid today so we can reduce the pH and from what I've learned in Pool School, I'm thinking that will also bring the TA down as well.

Edit: When the pool was first built, I believe the builder had the "Pool Chlorinator" and "Spa Chlorinator" set to 85%. We started noticing high FC right away, and I didn't know *anything* about pool chemistry at that point, and definitely didn't know how to operate my equipment. The builder came out and told me that he reduced the chlorinator setting to 65%. Today, I figured out how to reduce it to 45% and I'm hoping that it will help the FC levels.

Should I be doing anything else?

FC 23.5
CC 0.0
pH 8.0
TA 90
CH 350
CYA 90
CSI 0.07
Salt 3000
Temp 65F

Thanks for your help, and I hope to be an active member of the forums (after I learn a lot more!)

 

[ajw22]

The FC/CYA chart is your reference for safe CL levels. Anything under shock value for your CYA is safe. You are good up over 31 at CYA 90.

You need to reduce SWG% output or pump runtime or both in the winter. Shorter days and less sunlight you lose less CL. Then you need to turn things up in the summer.

Lower your pH down to 7.6 when necessary. Your TA will come down over time naturally.

Do a Overnight Chlorine Loss Test to see if those brown areas are algae. If not, they may be some type of metal staining.