Quote Originally Posted by PoolDoc
You'll probably get better results with low pH (~7.2) than with high pH (> 7.6) . . . UNLESS you had high CYA when you closed the pool, and now have low CYA. (Test to find out!). In that case, you'll need to RAISE the pH to around 8.0 with borax before you began dosing with chlorine. You'll get very fast algae kill, in that case, but you'll have to continue adding chlorine long after the water is clear, to get rid of all the chemical residue from bio-degraded CYA.
1)What do you do if you don't know what the CYA levels were when the pool was closed?
2}What would be the effects of having "all the chemical residue from bio-degraded CYA?"
3)How much chlorine would you add, and for how long after the water is clear?