I just woke up and retested the water, ph is still low (measuring yellow on strips and drop tester.) I added the other 1/2 box of borax. I will retest in 6 hours. I have another question, a few people have said my low ph is very dangerous. What exactly can happen? Is is bad for swimmers or the pool and equipment?. I have not let anyone swim since I found this problem. Thanks for your help.