I have been having issues keeping Chlorine in the pool.
Back ground
In-ground Vinyl 19k gal with 18 month old SWG and Hayward 5030 Cartridge filter. 2nd owner. I do know previous owner used pucks and copper based algeacide.
What I have seen to date:
1. Last year my CYA test (Taylor 2006a kit) registered off the chart
2. Did 20% partial drains twice during season
3. Chlorine stayed in range 3 to 5 ppm all season with bi weekly adding 1 lbs calcium hypochlorite to "shock". Only used DryAcid/Soda Ash and Baking Soda all season to keep water in check.
4. Had to do 2 x 20% partial drains over the winter because previous owner went cheap on a mesh vs solid cover.
5. Opened pool and had no issues(except green hair) until adding ascorbic acid to remove stains. CYA still over 100. Chlorine dropped to 0 over night during treatment
6. Went to pool store. 1 ppm copper, Calcium low, high phosphates, "shock", more Metal Sequestrant. Bought what they sold me.
7. Nothing changed after removing phosphates except chlorine held a little longer.
8. Found this forum and poolmath so no longer trust pool store.
9. did a SLAM #1. FC to 35 held fine over night though had SWG on. Thought I was done. Maybe not
10. Added 40 ppm borates via Boric Acid
11. Pool held FC over night just fine in fact it rises due SWG (5 to 6 PPM)
12. As soon as sun comes out it drops quickly to near 2 ppm and then recovers overnight but that has been getting worse over the days.
13. More research here.
14. Started Slam #2 with the following numbers and very clear water.
FC 2.5 (Have SWG but needed to add 1 gal of chlorine during day to get it there)
CC 0
PH 7.2 (only use Soda ash/Dry Acid)
TA 100 (Need to get this down a bit but use Baking Soda to raise when needed)
Borate 40 (Boric Acid)
Cal - 240
CYA - My test says 90 pool store says 30.
Got to FC to 38ish ppm last night after sun down and kept filter on water started to cloud up.
6:30 AM FC read 38 PPM and water still cloudy (did I pass?)
12 PM FC down to 26 PMM added more bleach per calculator (makes me now think I didn't pass am I right?)
What's concerning to me is that rapid FC drop as soon as sun comes out and the variation in the CYA results(I read the thread where someone else had that issue but no final answer was posted)
Why would FC hold overnight and dissipate so rapidly as soon as the sun comes out?
Just ordered the CYA 50ppm calibration agent to see what I get.
Any other thoughts?
Back ground
In-ground Vinyl 19k gal with 18 month old SWG and Hayward 5030 Cartridge filter. 2nd owner. I do know previous owner used pucks and copper based algeacide.
What I have seen to date:
1. Last year my CYA test (Taylor 2006a kit) registered off the chart
2. Did 20% partial drains twice during season
3. Chlorine stayed in range 3 to 5 ppm all season with bi weekly adding 1 lbs calcium hypochlorite to "shock". Only used DryAcid/Soda Ash and Baking Soda all season to keep water in check.
4. Had to do 2 x 20% partial drains over the winter because previous owner went cheap on a mesh vs solid cover.
5. Opened pool and had no issues(except green hair) until adding ascorbic acid to remove stains. CYA still over 100. Chlorine dropped to 0 over night during treatment
6. Went to pool store. 1 ppm copper, Calcium low, high phosphates, "shock", more Metal Sequestrant. Bought what they sold me.
7. Nothing changed after removing phosphates except chlorine held a little longer.
8. Found this forum and poolmath so no longer trust pool store.
9. did a SLAM #1. FC to 35 held fine over night though had SWG on. Thought I was done. Maybe not
10. Added 40 ppm borates via Boric Acid
11. Pool held FC over night just fine in fact it rises due SWG (5 to 6 PPM)
12. As soon as sun comes out it drops quickly to near 2 ppm and then recovers overnight but that has been getting worse over the days.
13. More research here.
14. Started Slam #2 with the following numbers and very clear water.
FC 2.5 (Have SWG but needed to add 1 gal of chlorine during day to get it there)
CC 0
PH 7.2 (only use Soda ash/Dry Acid)
TA 100 (Need to get this down a bit but use Baking Soda to raise when needed)
Borate 40 (Boric Acid)
Cal - 240
CYA - My test says 90 pool store says 30.
Got to FC to 38ish ppm last night after sun down and kept filter on water started to cloud up.
6:30 AM FC read 38 PPM and water still cloudy (did I pass?)
12 PM FC down to 26 PMM added more bleach per calculator (makes me now think I didn't pass am I right?)
What's concerning to me is that rapid FC drop as soon as sun comes out and the variation in the CYA results(I read the thread where someone else had that issue but no final answer was posted)
Why would FC hold overnight and dissipate so rapidly as soon as the sun comes out?
Just ordered the CYA 50ppm calibration agent to see what I get.
Any other thoughts?
Well, two things really jump-out at me first - excessive copper (green hair) and the elevated CYA. Both of those would still require a water exchange to remove metal and excessive stabilizer. So before doing anything else, I would evaluate the need to do another good water exchange. If allowed to remain, the copper will continue to be a problem with hair and stains to the pool. Since you are also doing a SLAM, the lower CYA will require less bleach. So other than the inconvenience of the water exchange process and cost of some water, that would be my first recommendation. How much water to exchange is really up to you to a great degree. The more the better (without going lower the 24"), but that would be my first step.
We hate to see anyone waste time and chemicals on water that's going to go into the grass. So definitely lower that CYA as much as you can so that you are sure it is in a manageable range. Keep in mind that if the CYA is over 100, even if verified with the dilution testing, matching the proper SLAM FC level can be tricky. If you can afford to exchange enough water to get the CYA down to about 70-80 or so, that would be a great goal. Do what you can and let us know if we can help. You've learned a ton already simply by taking charge of your pool.