I've been reading the forums on algae, CYA, and FC... and frankly, I have a puzzle.
After finally letting my pool guy go, who had been dosing the pool with 3 tri-chor tabs in the skimmer every week, and telling me my water was "all locked up", and needed a compete drain, I went to Leslie. Seemed like a good plan. The basics were moderate green algae, pH 6.8, FC 0, and a (probably incorrect CYA of 50), they had me shock the pool with 4 lbs of di-chor, reinforced with another 2 lbs over the next 48 hours.
Now, about a month later, and after learning the bad effects of di-chor, and tri-chor on my pH and CYA, I'm trying to go to BBB.
The short story is the pH is recovered, now 7.6. I've backwashed 500 gal a day and refilled daily for two to three weeks, about 50% of the total volume, which should have also reduced the total dissolved solids from 1900 to about 1100.
Now the puzzle.... my CYA appears to be ~300 ppm (by a Taylor K-2006 "dot" test with a 5x dilution, confirmed by Aquachek strips). I have a backwash model, and that would suggest I had a CYA of 510 ppm at end of the Leslie di-Chor shock and 6 months of tri-chor tabs. (Leslie tested CYA of 50 before the shock, and 150 after???)
But... I cannot maintain a FC of more than 3-4, even adding a gallon of 8% bleach every day. TAC is also 3-4. I have a chlorine loss of ~2 ppm/day (Tucson, sun, wind). Despite the high CYA and low FC, I only have very mild algae, visible as a subtle cloud ahead of the brush daily. Overall, the water looks great, is clear, and quite pleasant.
So, with such a low FC and high CYA, why is the algae reasonably under control?
And, why can't I establish and maintain a higher FC?
Should I continue the daily backwash, which would take to the end of July to get to a good CYA level? Try bio-active? Just live with the high CYA and low FC and wait for winter?
BTW, I'm on a well, and in a desert. A complete drain and refill is not really an option, 500 gals a day is about all the well, and the wash where the pool backwashes will take.
After finally letting my pool guy go, who had been dosing the pool with 3 tri-chor tabs in the skimmer every week, and telling me my water was "all locked up", and needed a compete drain, I went to Leslie. Seemed like a good plan. The basics were moderate green algae, pH 6.8, FC 0, and a (probably incorrect CYA of 50), they had me shock the pool with 4 lbs of di-chor, reinforced with another 2 lbs over the next 48 hours.
Now, about a month later, and after learning the bad effects of di-chor, and tri-chor on my pH and CYA, I'm trying to go to BBB.
The short story is the pH is recovered, now 7.6. I've backwashed 500 gal a day and refilled daily for two to three weeks, about 50% of the total volume, which should have also reduced the total dissolved solids from 1900 to about 1100.
Now the puzzle.... my CYA appears to be ~300 ppm (by a Taylor K-2006 "dot" test with a 5x dilution, confirmed by Aquachek strips). I have a backwash model, and that would suggest I had a CYA of 510 ppm at end of the Leslie di-Chor shock and 6 months of tri-chor tabs. (Leslie tested CYA of 50 before the shock, and 150 after???)
But... I cannot maintain a FC of more than 3-4, even adding a gallon of 8% bleach every day. TAC is also 3-4. I have a chlorine loss of ~2 ppm/day (Tucson, sun, wind). Despite the high CYA and low FC, I only have very mild algae, visible as a subtle cloud ahead of the brush daily. Overall, the water looks great, is clear, and quite pleasant.
So, with such a low FC and high CYA, why is the algae reasonably under control?
And, why can't I establish and maintain a higher FC?
Should I continue the daily backwash, which would take to the end of July to get to a good CYA level? Try bio-active? Just live with the high CYA and low FC and wait for winter?
BTW, I'm on a well, and in a desert. A complete drain and refill is not really an option, 500 gals a day is about all the well, and the wash where the pool backwashes will take.