help on affects of rain on chemistry

[pinstripepat]

All,

This is my first year with a pool and I have had to learn all summer the best way to miantain chemistry. Thanks to this forum I have ahd wonderful water and anytime I have had issues I come here. Well now may be another one of those times.

I have seemed to settle in for about a month or two now at about a FC of 6-7..... CC is notmally 0.0 - 0.5, mostly 0.0..... PH of anywhere from 7.4-7.8 (i adjust with muriatic)....... a TA of 90-110............. CYA of about 70........ and CH of about 400-490 (this is high I know but in talking with neighbors and PB our water is hard to begin with and I haven't drained yet to get it down) curious because my tap water tested at about 150 CH.

Anyway, to my shock the other day i did my normal FC test and it was 3.0-3.5 after months of 6-7 with my SWG on same setting. my TA was also 70.....now at the time I didnt give it much thought but we did have our first significant rain in porbably 1 1/2 months as is normal in a Texas summer. I am hoping it is not my salt cell after all has only been in use since May. Then I started reading about rain. Is it possible that the rain did this to my FC and TA and how can I tell. We also, just got rain again this weekend and I was going to shock Tuesday after it is suppossed to clear out. I am really confused by the drop in FC and TA.
Can anyone offer any suggestions or explanations before I call PB to check out the cell? Is it the rain? Thanks all.....
ONCL is still under 1 ppm even though I am at 3.0-3.5. I turned the cell up to 65% yestreday and my reading last night was 4.0 so it was a bit higher.

 

[JasonLion]

Chances are the SWG cell is fine. If there is a problem, it would probably be calcium scaling, which can be checked by a quick visual inspection of the cell. If you see any white crusty deposits on the cell plates, the cell need cleaning.

The reduction in TA is expected, and a direct result of acid additions to maintain the PH. We recommend TA be between 60 and 80 with a SWG, so TA is fine.

Large storms, particularly storms with lots of wind, and blow organic debris into the pool, which can lower the FC level. The SWG also needs to have it's percentage setting turned up higher when the water temperature is higher (I'm assuming your water is warmer than it was June).

 

[pinstripepat]

Yes, with temps in 100's for most of July and August my water temp was in low 90's. Recenlty we have dropped into the low - mid 90's in air temp and water temp has gone down to about 85. Forecast calls for back near 100 by weeks end.

Is it easy to chekc the cell, I have a Jandy Aqua Pure? Looks like it has two unions on each end, or should I have PB come by and show me first time?