Why add Borates to your pool?

[chem geek]

:? Have I messed up? I have never added Borax. I thought it raised PH. The only thing I've added is Baking Soda and Bleach. Occasionally, I will use the pucks (I know, smack me). Water tests have all been reading within normal range as long as I keep on top of the bleach and baking soda.

Borax has TWO very different uses. When added in small quantities by itself, it raises the pH without raising the TA by as much as sodium carbonate / pH Up / Arm & Hammer Super Washing Soda. However, when a large amount is added along with acid to keep the pH the same, then a level of 30-50 ppm of Borates in the water acts as an algaecide. You can still use small amounts of Borax by itself to raise the pH even if you already have Borates in the water. Just keep in mind that the Borates don't break down so their amount should be monitored once in a while (similar to CYA or CH).

Richard

 

[Rangerman]

This link is directly to the spreadsheet while this link is to a ZIP file of the same spreadsheet. This ZIP file link is also found at the end of the first post in this thread. The spreadsheet calculates lots of pool water chemistry parameters and is not for novice users. To calculate your situation, I just entered 50 in the "Goal" area for Borates (and made sure the setting under "Base to add to increase pH" was set to "20 Mule Team Borax"), then scrolled down to see how much in Borax to add in the blue fields (under "Borates") and entered that into one of the orange fields (I used ounces weight). I then went back up to the top of the spreadsheet and clicked on the "Calculate Acid/Base/TA" button and saw the result for the amount of acid to add (because I kept the Goal pH was the same as the Initial pH).

The amount of acid to add to compensate for the pH change from Borax is always the same proportion (assuming the normal 31.45% HCl strength of Muriatic Acid). Every box (76 ounces weight) of 20 Mule Team Borax requires 36.3 fluid ounces (about 4-1/2 cups) of Muriatic Acid to keep the pH the same.

Richard

Whoa ... I'll have to study this awhile. Thanks.

 

[gonefishin]

Another possible use for Borax?

I came across this website in my readings...thought I'd pass it along.

dan

 

[Lenny]

I added 7 or so boxes of Borax earlier in the summer and it's buffering effect has been impressive. I haven't added ANY acid in 3 or 4 weeks. The PH locked in at 7.7 and has hardly moved.