As usual, one can never be too clear when posting to a forum. My apologies.

My 24 ft AG 4 ft high so that makes it 12,000 not 10,000. Don't know what I was thinking there...

The cya did not disappear overnight, it was probably about 1 week between tests. We did have some rain, but it only added a few inches, if that.

I have the Taylor test kit I got new this year and do it outside in the evenings. Based on Ben's kit instructions, I wait at least 30 seconds after mixing before testing, but I see that I should wait longer. I like the idea of mixing cya first, then testing everything else, then looking for the black spot.

I have already gone through 1 bottle of taylor cya reagent so I will order a large refill bottle.

When I add CYA I use a sock in front of the return and it takes about 1 day to dissolve a 1 or 2 pound bag/bottle. I can't remember the size, I'll have to pay more attention.

We are not a green swamp, the water is clear. But yesterday, we could see some algae trying to get started on the bottom. We vacuumed and backwashed.

---Dale