I started adding borates to my pool a few months ago. Following the directions to test monthly, I did the first month and the level had dropped so I added borax to return to the desired 50. I just tested today and the level was 80 (I am using the LaMotte test strips). Why would it rise and do I need to bring it down? I don't recall seeing information in "So you want to add borates to your pool - why and how" regarding a rise in the level.