Ah okay. Gotcha. I think I may go to the dreaded pool store tomorrow just to compare their readings of the water to mine. I'm curious to see how closely I am interpreting things. :-) How about that other thing I asked above....My PH was low so according to the pool calculator, which BTW I like so much that I bought the app today, so I added the suggestion amount of Borax. How long should I wait to retest ph? I ask because I went ahead and retested after about 2 hours and now the Ph is off the chart high. I'm hoping that is because I am just too impatient.