Firstly, my apologies for posting another message about chlorine levels. I have spent quite some time reading through prior posts, but none quite match my situation.
I have a 12000 gallon pool with a hayward sand filter. We drained and refilled the water recently. I have finally got the CYA levels up to 40-50 last week. The acidity is a little high last I checked, but nothing serious and all other levels are where they should be, and they stay pretty consistent. The water has been crystal clear and wonderful.
My problem, however, is that I cannot maintain free chlorine levels. I added enough 8.25% bleach last night, for example, to raise the fc levels to around 7. This morning the FC was about 6, which I thought was fine. Now, late afternoon and the FC is zero! It's been like this for the past two weeks and the grocer at the supermarket is starting to eye me suspiciously because I am buying liquid bleach so frequently!
Seriously though, apart from our excessive 100+ heat here in Phoenix, I do not know why I am loosing FC so quickly and I am very frustrated and I would apprecate some advice. My CYA levels are fine so I don't think that is the problem and I haven't seen any cloudiness or discoloration at all that would suggest organics eating the chlorine. the water is so clear, but I am so frustrated!
Here are my current specs (late afternoon):
Fc - 0
TA - 170
Kit: taylor k2006 fas-dpd
Thanks up front for any suggestions!