Opened my pool last weekend and it was super clear. It turned green at some point this week, even though the water was only 52 degrees. It was too cold to run my SWCG and I didn't worry about it cause I thought water was too cold for algae to grow... gotta learn some lessons the hard way I guess.
Anyway, just wanted some advice on my calculations so that I do this right and minimize the monetary damage as much as possible.
First of all, the pool store sold me on a strong algaecide, some type of polyclot that is strong, 60%, I guess I need to use that to break up the algae so that it doesn't continue to produce more algae even after that algae bleached out. Is this accurate? I don't see this mentioned in pool school under the fighting algae section. Thinking maybe they are just selling me on an expensive product?
Here are my #s. (tested at pool store) The chlorine was brought up to this level from zero by adding 7 lbs of shock last night.
42,000 gallon gunnite pool
FC = .6
TC = 1.0
ph = 7.8
alkalinity = 270
CYA = 40
So according to the CYA/Chlorine chart I'm aiming for a shock level of 24. (or under, it doesn't list 40 CYA in the chart)
The pool calculator is telling me I need 873 ounces of 14% chlorine, (the tested level of the chlorine I just bought at pool store)
First, should I add 1/2 - 3/4 gallon acid to bring my alkalinity down and my ph down a bit first?
Do these #s look right? Am I doing anything wrong?
Should I add the algaecide mentioned above?
Should I wait till evening to add liquid chlorine to get the maximum effectiveness? It's overcast here today so sun won't suck out chlorine too much. Or should I just get the chlorine in their ASAP?
Thanks in advance for the help