Motorized cover, covered most of the day
I have a TF100 kit. I tested 2 weeks ago and got a 0 reading for CYA. Previously used 3" pucks to chlorinate so I figured there had to be some CYA in there but maybe it just wasn't reading in the test. Added enough CYA, per poolcalculator, to bring CYA to 20, figured I'd start slow and re-test. I re-tested yesterday and I still get a CYA reading of about 0. The rest of the numbers are:
3 days ago
PH: 7.0, been having a hard time getting this up with borax.
CYA: 0, or I can still see the black dot with the tube full, pretty much clear
Water has been crystal clear until 3 days ago, it was very slightly green. Should have been more diligent with my bleach.
So I shock. I'm adding bleach as if it had CYA of 20 since I've read on here that sometimes you will have 15 or 20 CYA even with no reading, and since I added granular CYA to bring to 20, I've went with that.
Add enough bleach to bring FC to 12. I've been trying to re-test as often as I can since I'm at work during the day, but I've been testing in the morning, then mid-morning, then lunch, then mid afternoon, then at night. I've been adding enough bleach to bring FC to 12 each time. Cover has been kept on during the day so I wouldn't lose any chlorine to the sun. The FC has always been between 2 and 5 and the CC has been between 2 and 4. This morning I tested about 6:45am. FC was 3 and CC was 2. I add bleach to bring FC to 12. Test again at 7:45am, FC was 2.5 and CC was 2.5.
How can it use that much chlorine in one hour? And the CC going up now? I've thought I was doing something wrong with the test but I've followed the directions exactly and have been very careful with everything.
Oh and after about a day and a half, the pool had no more green tint and is almost perfectly clear, maybe a slight blueish tint. There are no visible signs of the algae anywhere although I know it's not gone yet, right?
So I'm thinking maybe there's more CYA than is showing on the test and I need more chlorine. I really don't know anymore.
Oh and I've been running the filter 24/7 while I've been trying to shock. The psi has only went up 1 so far.
Anyone have any ideas? Hope I haven't forgotten any info that you would need to help. Thanks.