- Apr 22, 2020
- 13
- Pool Size
- 18500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
I'm a victim to the CYA disappearance after FC went to zero when the SWG stopped while out of town. Last known CYA was around 40.
Given the warm temperatures and sunny days, I'm limited to SLAMming in the evening/overnight so not to lose FC to sunlight given the high SLAM FC levels. After reading up on this unfortunate situation here on TFP, I have the following questions for any help or comments from the group:
1. How quickly can FC be measured after adding large amounts of liquid chlorine to ensure an accurate reading by mixing with the entire pool? Pump is on high, and adding to the skimmer and in front of my single sidewall return (other returns are on the pool floor). I have been waiting ~1 hour, but that limits the cycles in an evening.
2. Measuring no ammonia and CC down to 0.5-1, I added CYA last night to get to around 20 using the sock method with me periodically massaging it to dissolve it faster. This morning could not see measurable CYA (yet?). Was this too soon to add CYA? SWG is on continuously to keep some FC coming in during the sunny days while trying to complete the SLAM.
3. Worried that the new CYA addition may be subject to the original problem and don't want to add more until I see some FC consumption slow down. So far, a total of 65-70 ppm FC added, but may need to go up to 100 or so given possibly max of 40 CYA before this started based on the 2.5x ballpark from previous threads (thanks chem geek). FC dropped from ~12 to 1.5 in 6 hours last night, CC ~1.
This is turning in to an unfortunate, but interesting, science project. I'm hypothesizing that my lack of ammonia readings indicates that the intermediate forms are consuming the FC, and that I need to just keep pumping in the 10% bleach. I assume there is no need to do this all in one evening, as the FC is being used effectively as it is added, and will eventually be sufficient and result in stable FC at some point, after which I will increase the CYA level.
Thanks for any comments and suggestions!
John
Given the warm temperatures and sunny days, I'm limited to SLAMming in the evening/overnight so not to lose FC to sunlight given the high SLAM FC levels. After reading up on this unfortunate situation here on TFP, I have the following questions for any help or comments from the group:
1. How quickly can FC be measured after adding large amounts of liquid chlorine to ensure an accurate reading by mixing with the entire pool? Pump is on high, and adding to the skimmer and in front of my single sidewall return (other returns are on the pool floor). I have been waiting ~1 hour, but that limits the cycles in an evening.
2. Measuring no ammonia and CC down to 0.5-1, I added CYA last night to get to around 20 using the sock method with me periodically massaging it to dissolve it faster. This morning could not see measurable CYA (yet?). Was this too soon to add CYA? SWG is on continuously to keep some FC coming in during the sunny days while trying to complete the SLAM.
3. Worried that the new CYA addition may be subject to the original problem and don't want to add more until I see some FC consumption slow down. So far, a total of 65-70 ppm FC added, but may need to go up to 100 or so given possibly max of 40 CYA before this started based on the 2.5x ballpark from previous threads (thanks chem geek). FC dropped from ~12 to 1.5 in 6 hours last night, CC ~1.
This is turning in to an unfortunate, but interesting, science project. I'm hypothesizing that my lack of ammonia readings indicates that the intermediate forms are consuming the FC, and that I need to just keep pumping in the 10% bleach. I assume there is no need to do this all in one evening, as the FC is being used effectively as it is added, and will eventually be sufficient and result in stable FC at some point, after which I will increase the CYA level.
Thanks for any comments and suggestions!
John
Do that first.