Got this pool for my grandson and want to be sure the water is right for him Filled 1,052 gallon pool on Monday and put chemicals. The pool pump has run for a total of 12 hours in the last 24 hours. Tested the water ta200 free chlorine 3.0 total chlorine 3.0 pH is below 6.8 I'm assuming I need to add soda ash but I don't know how much to start with for my size pool Tia for the help