I just purchased a house that has a 13500 gal IG Gunite DE pool that hasn’t been maintained for about a month. I have a few questions around pool ownership in general and some specific to my pool. I’ve spend a few days doing as much research as possible but I still have some questions.
I took a water sample to the local pool store and got the readings below.
FAC = .5
pH = 7.6
TA = 100
CYA = 60
CH = 450
I was surprised that they did not include a reading for total chlorine. After all, don’t you need to know the total chorine to find the combined chlorine in order to shock it away?
Pool guy said my pool was mostly in balance with the exception of it needing a shock and I should drain 50% of the water to combat the hardness towards the end of the season.
He sold me Power Powder Pro (73% cal-hypo) with instructions to dump two pounds of it in the pool two days in a row. Doesn’t cal-hypo add calcium to the water? Shouldn’t I use bleach instead?
How did the pool guy determine the amount of chorine needed in order to shock the pool? This is probably my biggest question. I’m unable to calculate the amount of various products needed in order to shock. (Yes, I have looked at poolcalculator.com but I don't know what my target should be) I thought I remembered reading somewhere that you need 10ppm AC to convert 1ppm of CC. Is that right? If it is, then I would just need to find out how many ppm of CC I have and put 10x that amount of AC right?
EDIT: On a side note, I've looked at the "Chlorine / CYA Chart" but I'm unsure how to read it.