Will Borax cause a rise in CH?

[Sandrat]

I am adding borates to my pool. All my local store had was 5 boxes of 20 mule team, so I decided to buy them and see how it tested afterwards (went from o borates to 15).

After I added them, my CH, which was testing at about 250, now tests at 450. I've looked high and low in the forums and on the web, and I don't see any warning or discussion of Borax driving up CH.

Before someone suggests it, I have been a pool owner for 20 years. I do my own testing with a Taylor 2005 kit (and an additional TFT FAS kit). I don't think it's in my test methods (but I've made mistakes before).

I really don't want to draw down the pool to lower the CH. I've been gradually getting the CYA where I want it through a slow addition of dry acid.

AFWIW, I will do the rest of the borate addition through boric acid, via DudaDeisel. This is the only way to go. Less of the boric product, and no hassle of Muriatic acid.

 

[Mr Bruce]

Short answer, no.

Is it possible you used a 25ml sample and counted by 10s?

e:clarity

 

[JoyfulNoise]

There is no calcium in Borax therefore it cannot raise your calcium hardness. It must be something in your testing methodology.

What chemical is listed on the box?

 

[camueller]

In my experience, i think it can actually lower your calcium by causing some of it to precipitate and get filtered out of the water (or stuck to tile) due to the high pH of the stuff and the high concentration of it in the water immediately around the area you dump it into your pool.

Of course, a little bit of borax isn't going to change it much. Probably not enough to even notice on a test.