I noticed in the Pool Calculator that when borates are added to a pool, the amount of muriatic acid needed to lower the pH by a specific amount goes way up (more than doubles even with borates at 40ppm.) I"m curious if the effect of the acid on TA changes as well -- i.e. do you still get the same amount of TA drop from MA that you did before adding borates?
I'm considering adding borates in order to slow the significant pH rise in my pool, but given that my TA tends to steadily drop to 40 or so due to my twice-a-week acid additions, I'm wondering what will happen with regard to the longer term effects on TA drop after adding borates. Will the pH rise slow down enough to completely compensate for the higher amount of acid needed to raise it? Or, will I end up having to chase the dragon trying to keep the TA up to a reasonable level while adding higher acid doses at a slower interval?
I guess the information I'm looking for is some idea of how much effect on pH rise to expect from the borates. I know that this will vary from pool to pool, and that there are factors in play that there aren't any solid numbers for (such as how fast the pH actually rises), but I'm looking for general guidance here. For example, does adding 50ppm borates approximately "halve" the pH rise, or does it do more (or less) than this typically? If I halve the pH rise, but need to add twice as much MA half as often, I haven't changed things all that much.