PH Questions

[chem geek]

I don't know about #1 -- the Taylor K-1000 pH test (and I believe Ben's kit) will read to 8.2 while the Taylor K-2006 kit will read to 8.0, but I'm not aware of kits that read higher.

#2 is pure bunk. The "acid column" or "slug" method was debunked here. Basically, no matter how you add acid, the TA will be lowered. 25.6 fluid ounces of full-strength Muriatic Acid (31.45% Hydrochloric Acid) in 10,000 gallons will lower the TA by 10 ppm no matter how it is added. The only difference is that depending on the amount of aeration, the pH may not drop as much because aerating the water has the pH rise with no change in TA. Be very careful because dumping the acid in one place without circulating can be damaging to pool surfaces since the pH will be very, very low and will tend to pool near the bottom if it doesn't mix so this should never be done (and it's not effective anyway so why bother).

You should read Water Balance for SWGs where you can learn how to slow down the rate of pH rise. Lowering your TA should help (this was first figured out in this thread). The use of 50 ppm Borates can also help (this was first figured out in this thread). Having the CYA level higher at 70-80 ppm can also help if your pool is exposed to a lot of sunlight (but you need to maintain a minimum FC of 4 ppm in this case).

Richard