hi all!
This is my 2nd season with this pool. Last year i bumbled my way through and found TFpool way too late in the season, and i have a specific question about why my FC disappeared in the last two days.
Opened May 8th, 36k gallon in-ground pool with SWG, heater, and new VS pump, taylor test kit.
Pool company initially shocked it at opening. FC levels were 5-10 based on my Taylor kit for over a week. I was not running the SWG at first because the water was cold. For the last week the water temp is in the 80s. I got my CYA level up to 70-80 which gives me a target FC of 3-6.
On 5/15 i dropped the SWG from 50% to 20% because FC levels were still 5-10 (pump running about 14 hours per day)
On 5/16 i dropped SWG to 10% because FC levels were still 5-10
On 5/18 FC level finally dropped to 3-6. everything was in balance. pH 7.4, TA 90, salt 3400 ppm, CC zero
On 5/20 FC level still 3-6, nothing changed
On 5/22 FC/TC/CC levels all undetectable on the Taylor kit
I guess i should have checked 5/21 as well, but i didn't that day. I did not use such a high CYA level last year (i didn't know it was recommended) and i figured that higher CYA accomplishes three things (but maybe this is wrong)
1) lets my chlorine last longer
2) requires me to run a higher FC than i did last year (when i had a much lower CYA level)
3) lets me run my SWG less
Point # 3 is why i was OK with the idea of running it at 10% (last year i ran a much lower CYA and had the SWG running 60% generally), but i don't know why it suddenly went from 3-6 to undetectable two days later. I felt the CYA would give me a more gradual drop off of the FC levels.
Right now i'm running my SWG at 100% to try and bring it back up quickly (supposed to go in it for the first time this eason today!)
So what i don't understand is that steep drop off of the FC level from 5/20 to 5/22. The pool is perfectly clear and CC is zero, so i don't think it got eaten up by anything.
This is my 2nd season with this pool. Last year i bumbled my way through and found TFpool way too late in the season, and i have a specific question about why my FC disappeared in the last two days.
Opened May 8th, 36k gallon in-ground pool with SWG, heater, and new VS pump, taylor test kit.
Pool company initially shocked it at opening. FC levels were 5-10 based on my Taylor kit for over a week. I was not running the SWG at first because the water was cold. For the last week the water temp is in the 80s. I got my CYA level up to 70-80 which gives me a target FC of 3-6.
On 5/15 i dropped the SWG from 50% to 20% because FC levels were still 5-10 (pump running about 14 hours per day)
On 5/16 i dropped SWG to 10% because FC levels were still 5-10
On 5/18 FC level finally dropped to 3-6. everything was in balance. pH 7.4, TA 90, salt 3400 ppm, CC zero
On 5/20 FC level still 3-6, nothing changed
On 5/22 FC/TC/CC levels all undetectable on the Taylor kit
I guess i should have checked 5/21 as well, but i didn't that day. I did not use such a high CYA level last year (i didn't know it was recommended) and i figured that higher CYA accomplishes three things (but maybe this is wrong)
1) lets my chlorine last longer
2) requires me to run a higher FC than i did last year (when i had a much lower CYA level)
3) lets me run my SWG less
Point # 3 is why i was OK with the idea of running it at 10% (last year i ran a much lower CYA and had the SWG running 60% generally), but i don't know why it suddenly went from 3-6 to undetectable two days later. I felt the CYA would give me a more gradual drop off of the FC levels.
Right now i'm running my SWG at 100% to try and bring it back up quickly (supposed to go in it for the first time this eason today!)
So what i don't understand is that steep drop off of the FC level from 5/20 to 5/22. The pool is perfectly clear and CC is zero, so i don't think it got eaten up by anything.