Balancing CSI and Chemicals in General

[KAsarge]

Hi all,

Looking for some help, guidance and advice on what I should be doing. You will find my specs in my signature but I am 20k plaster pool on a SWG in North Carolina. I test every three days using the taylor test kit. My most recent results are

Free Chlorine: 5.2 (ran super chlorinate late last week) I try to keep it in the 3's
PH: 7.8
Alk: 70
Calcium Hardness: 350
CYA 70
Water Temp : 85
Salt: 3100

That gives me a CSI of -.05 which is great except the pool school guy gave me different ranges for chemicals.
He suggests PH in the 7.4-7.6 range. If I go to 7.4 my CSI drops to -.42 (image below)
He also suggests Alkalinity in the 80-120 range. I know from reading just to let it settle and keep it above 50. If I let it drop to 50 with a 7.4ph and keep other chems the same, that drops my CSI to -.65.
Finally, he suggests calcium hardness from 200-400 while pool math says 250-650. Any specific reason as to why the huge delta between suggestions?

In short, it seems that TFP suggestions somewhat counter each other. If I keep my alkalinity low, my CSI soars.

And finally, I keep getting this white stuff settling at the bottom of the shallow end of my pool. I'm guessing its coming from a jet that points in that direction. I pulled my salt cell and its clean, so not sure if its scale breaking off somewhere or what.

 

[YippeeSkippy]

My advice- "Stop listening to that crazy outdated fool who gave you pool school!!"
Don't chase pH and TA. Keep your pH in the 7's, and TA between 60-90, and your pH won't rise as fast.
Keep your FC higher as you're at risk of algae with it that low. You want it high enough that even without swimmers you *will* lose FC daily to the sun so if its kept high enough it is still is over your bare minimum. See chart below:


The variations in our levels to the old fashioned pool store advice is that we take into consideration more factors such as locale (Hot sunny climates, for example) as well as how they're being chlorinated (SWG vs Liquid vs Pucks), we know how to deal with locations that have super high calcium due to evaporation, etc.

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

www.troublefreepool.com

The white flakes appear to me as calcium which coats the SWG plates if the pH is too high.... pick some up and put it in the grass and drop a bit of muriatic acid or vinegar on it. If it fizzes, its calcium. Sometimes the plates get coated due to chemistry it happens once, and never again.

Maddie

 

[KAsarge]

Thanks for the help. So should I chase CSI? As I stated above, if I keep alkalinity at 70 and PH at 7.4, I’m looking at a -.42 CSI

Also, the white flakes appear once a week or so. It hasn’t been just once.

 

[mknauss]

Let pH rise to 8 before adjusting to 7.6. Likely the pH may sit at 7.8 a very long time unless you are adding high TA fill Water.