@WaterMom: the Taylor phenol red is good to FC=10. Above that, you can dilute 50:50 with distilled (not tap, spring, 'purified' etc. -- just distilled) water. That will allow accurate pH tests up to FC=20. Distilled water at Walmart => http://pool9.net/distilled/

@CarlD: Using washing soda (Na2CO3) + muriatic acid will certainly work. And, 10 lbs of soda ash will raise the TA about 40% more than 10 lbs of baking soda (NaHCO3). But the downside of that is that you have to buy the 'H' (free proton or acid) that baking soda already has (Na2CO3 vs NaHCO3). I'm pretty sure the economics work out in favor of baking soda, if your purpose is to raise the TA. Certainly, the safety does. Of course, "Dad2" is gonna have to handle MA regardless, because of the pH.

@Dad2handz: Do you have anything that is aerating your pool? A fountain, a bubbler, suction leak bringing air into the pool; an ozonator, or an overflow -- anything like that? Your figures (pH=8+; TA=50) look like those that belong to a pool that's being aerated. Aeration (1) raises pH of pool water and (2) strips alkalinity.

It's common for pools with SWCG's to struggle with a constantly rising pH, but the fact that you've got repeatedly high pH + low TA suggests that something else might be happening.

Bottom line? If you aerate constantly -- or even frequently -- you will have to BOTH add muriatic acid AND baking soda frequently, since you aerated your TA (really, CA or carbonate alkalinity, which is the major component of TA) off into the air as CO2 or carbon dioxide.

Using MA safely => http://pool9.net/ma/