Triggered by a remark of chemgeek in post Foam that isn't?
"By the way, don't forget to use Dichlor one day each month to help maintain the CYA level. You might test for the CYA level to be sure it's not too low. Chlorine slowly oxidizes CYA in hot tubs at the rate of roughly 5 ppm per month."
I was wondering if the sticky "How do I use Chlorine in my Spa (or pool)?" would need a remark about degrading CYA?
Until now i was under the assumption that CYA would last the water renuwal periode but now i'm wondering. If i understand it correctly than CYA would go lower in the period of time. So starting at 30 would mean about 25 at the end of the month.
A wise man would say: why not now meassure CYA, and he is so right. BUT in holland the summer is over so it would be very hard to get the optimal sun conditions to do a good CYA measurement
So perhaps next best thing (to keep cover allright) would be to add an amount of stabilizer each month to compensate for CYA loss.
For my spa i guess about 0.3oz (9 gram) of stabilizer (478gallon/FC 4/PH7.5/TA50/CH150/Borate50/temp102)
Or do i miss something?