Quote Originally Posted by chem geek
And generally add half the recommended amounts and see where you are at, even if the recommendation is from me.

I'm not sure why you swung so high in pH. Maybe your son didn't actually put in as much as he said or my calculations could be wrong (in which case, I'd like to find out and fix it). It's been right with others using Borax so I'm not sure what happened and I'm really sorry for any trouble this caused.

Richard
A full box of borax is 4 lbs 12 oz.....almost 5 lbs. That could explain the pH rise. 3/4 to 1 cup of acid should get you back into the ballpark by my calculations.