Ok, so 2 weeks ago we pulled the security cover back and welcomed a nice pond. We closed per instructions but it doesn't seem to matter here in Oklahoma where you can get 90 degree days in January followed by 6 inches of snow.
Anyway, I took initial readings and got:
PH 7
CC and FC 0 (of course)
Alk 70
CYA < 5ppm
I kicked up the Alk and then the PH and poured in some Poly.. Then last weekend we pull the cover back again to no change. So I decided to shock it. Since CYA was down, and the Chloro-brite I decided to use that.
Did 2 lbs of Chloro-brite and turned on the filters. Never did get a CL reading. Went back and bought some more and ended up putting 5 bag (lbs) in to get a 15 FC last night.
Wake up this morning and it's dropped a little (12 FC) so I put in another bag.
This evening I come home and measure and I get 15 FC.. It's been in the sun so I'm confused that it hasn't dropped and the pool is still a pond. I then go through and measure everything and I get.
FC 15
CC 1
Alk 90
PH 7.5
CYA 80 !!!!!!!
I'm using the FAS/DPD method to measure FC. When I use the regular method with dilution I'm getting 9 TC..
I try to keep CYA around 30 but had no idea it would rise that fast. So am I stuck draining/refilling? Anyone else have a clue what just happened?