- Apr 22, 2020
- 15
- Pool Size
- 18500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
A neighbor who had been getting help from "the local pool store" was saying they were having problems with the pool chemistry. I took my Taylor FAS-DPD test kit over yesterday and measured what I could, but given the high free chlorine levels, or something else going on, would like to run the situation by the group here.
18,000 gallon vinyl pool, has been using a pool cover for heat retention, with a propane heater
Has had the SWG switched off for the past few days. Hayward TCELL925. His last SWG setting was at 36%, single speed pump running 24x7.
FC on FAS-DPD test was 58, that was a lot of drops!
CC none
pH color immediately started out around 7.6 then quickly drifted to bright pink 8+. I have never seen something like this. Can this be due to high FC?
Acid demand drops impact didn't even seem to keep it on the same color scale. Not sure what the pH really was.
For alkalinity test, it went from blue to yellow (not green to red) around 50.
CYA was not measurable, clear to the top of the tube, so less than 20, and presumably zero with no apparent history of adding it.
CH 90, if that hasn't been adversely impacted.
Clarity 10.
Salt 3930, but only reading 2800 on SWG. No history of cleaning T-cell, so will show him how to do that which will likely fix the discrepancy.
Temp 77.5 F
Clearly need to lower the FC level by keeping the cover off, but that is likely to take a while. No water features or spillovers to help. It was likely even higher since the SWG should have been off for several days now. I set the dial to minimum (5%) just in case the internal SWG panel switch has failed (SWG power is tied in to pool pump circuit). Other option is to drain and re-fill, but he doesn't plan to keep the pool open much longer. I advised against using the pool given the current questionable status of levels.
My guess as to what happened was that he ran the SWG all summer at way too high of a level so that resulted in a slowly and ever-increasing FC level. The "pool store" had suggested he set it at 60%. I found it at 36% with the pump on 24x7. (For reference, my max SWG setting for a similar volume plaster pool was 18% for stable levels running 24x7 during the peak of summer heat and pool use with a CYA of 70. Mine is now at the minimum setting of 5% and holding FC at 6.)
Any thoughts on how a very high FC will impact the other tests? Could the pH be way out of line and impacting the FC readings? Given the strange color results on pH and alkalinity, I'm hoping someone here might have seen something similar at some point, or an explanation of what is going on with chemistry resulting in the odd test color readings.
Thanks for the help!
18,000 gallon vinyl pool, has been using a pool cover for heat retention, with a propane heater
Has had the SWG switched off for the past few days. Hayward TCELL925. His last SWG setting was at 36%, single speed pump running 24x7.
FC on FAS-DPD test was 58, that was a lot of drops!
CC none
pH color immediately started out around 7.6 then quickly drifted to bright pink 8+. I have never seen something like this. Can this be due to high FC?
Acid demand drops impact didn't even seem to keep it on the same color scale. Not sure what the pH really was.
For alkalinity test, it went from blue to yellow (not green to red) around 50.
CYA was not measurable, clear to the top of the tube, so less than 20, and presumably zero with no apparent history of adding it.
CH 90, if that hasn't been adversely impacted.
Clarity 10.
Salt 3930, but only reading 2800 on SWG. No history of cleaning T-cell, so will show him how to do that which will likely fix the discrepancy.
Temp 77.5 F
Clearly need to lower the FC level by keeping the cover off, but that is likely to take a while. No water features or spillovers to help. It was likely even higher since the SWG should have been off for several days now. I set the dial to minimum (5%) just in case the internal SWG panel switch has failed (SWG power is tied in to pool pump circuit). Other option is to drain and re-fill, but he doesn't plan to keep the pool open much longer. I advised against using the pool given the current questionable status of levels.
My guess as to what happened was that he ran the SWG all summer at way too high of a level so that resulted in a slowly and ever-increasing FC level. The "pool store" had suggested he set it at 60%. I found it at 36% with the pump on 24x7. (For reference, my max SWG setting for a similar volume plaster pool was 18% for stable levels running 24x7 during the peak of summer heat and pool use with a CYA of 70. Mine is now at the minimum setting of 5% and holding FC at 6.)
Any thoughts on how a very high FC will impact the other tests? Could the pH be way out of line and impacting the FC readings? Given the strange color results on pH and alkalinity, I'm hoping someone here might have seen something similar at some point, or an explanation of what is going on with chemistry resulting in the odd test color readings.
Thanks for the help!
