PH Questions

[Charlie]

Old age...
TA=60
I did add 2 cups of Arm & Hammer baking soda yesterday. I'm targeting 70-80.

I do not have Borates in the pool. Where or how do I go about getting some?

My pH does rise since I have a small water fall from the spa into the pool. As for targeting 7.5 as the low, yeah I've been trying to figure out how much to add so I have a general idea when its at 7.8 I add "xx" amount in. OK so I'll target a pH of 7.6-7.8 or even 8.

[chem geek]

The addition and use of borates is described in this thread. You can use The Pool Calculator to calculate dosages of 20 Mule Team Borax and Muriatic Acid, or of boric acid if you get that directly (see this post).

The Borates will make the pH rise slower and might lower the total cumulative acid addition needed over time if you are able to lower your SWG on-time due to the algaecidal properties of the borates. As for pH, I wouldn't go so far as 8.0. I think that after the borates a ph of 7.7 is going to be reasonable stable.

[Charlie]

Thanks Rich for that info. Interesting on how much of 20 Mule Team you need to add, which brings me to this question: since you are adding so much in the pool, what does that do to the DE filter pressure? Will I see a huge increase? My pool is ~14,500 gallons.

[chem geek]

You won't see any change in pressure -- I presume you are adding it directly to the bulk pool water. What you add to water is like adding salt -- it fully dissolves. It does have a small effect on Total Alkalinity -- 50 ppm Borates at a pH of 7.5 increases TA by about 5 ppm -- but you can use The Pool Calculator to calculate the saturation index and it will account for the Borates (assuming you put that into the calculator).