Hi TFP -- first month with new owner-build pool, and first month as a pool owner in general I'm testing pool daily (CH/PH), mostly so I have a feel for the rhythm.
I have the Taylor k-2005, but recently complemented the kit with the FAS-DPD test to kind of verify my ability to decipher the FAS test. I find the FAS test to be a lot more purple with the water sample and hard to compare the color range to the color indicator. That said, I feel better about it now with the FAS-DPD giving me confidence.
Ok, so here's my question. I have tested CYA 3 times. The first time I ever did the test I had low confidence in the process, but came up with "55". So I guess that means 60. A couple days later I took it to the pool store and they said it was 30. Honestly, I wasn't super confident in their test either, as another person behind the counter was correcting her interpretation of the CH levels. Ok fine. I have a range at least.
Two weeks later I lose about 1000 gallons after leaving the cleaner out of the water. Oops (lesson learned, will always unhook). I tested CYA again as a kind of controlled test, and came up with 35, but I'll call that 40. Now, I did get that number by shooting my phone light upwards in the tube. Had I not had the light, the number might've been higher. Note, I just discovered these instructions CYA Testing - Further Reading but only before I wrote this post.
So long story short, no matter how you slice and dice it, my CYA is likely lower than the recommendation for an SWG. However... I have been struggling a bit to keep FC down! I am in the Sacramento area, and the pool has >5 hours of direct sunlight, and temperatures range from 85-100 right now. I am surrounded by dozens of redwoods, but all are >30 feet away. Pool and spa are 20k gallons, and I have an IC40 with pump running about 11 hours a day. I have finally got chlorine lower by setting the SWG between 15% and 30%... finally settling on about 25%. This morning's CH reading is 3.4 using the FAS-DPD test. 3 days ago my CH was 4.0 and IC40 was set to 30% before I lost 1000 gallons.
My pool math would suggest I should lose about 1.5-2 PPM of chlorine a day, and should be running my pump about 50%. Pool seems to hold chlorine just fine, and I also have a Pentair BioShield. I now know the recommendation here about UV, but I have it and I'll assume it does something.
-- ok so... my question (finally)... what purpose would bumping CYA up be to say 60-70, if water is clear at FC PPM of 3.0 (or less), and I don't seem to be burning through FC. Are there other reasons? Assuming my tests is reasonably accurate, is there any risk of leaving CYA at 30-50, if I want to keep FC down 2.5-3.0 and this seems to be working? Will I just be surprised eventually with an overnight bloom of something, even with the bioshield as a kind of backup/complement?
I have the Taylor k-2005, but recently complemented the kit with the FAS-DPD test to kind of verify my ability to decipher the FAS test. I find the FAS test to be a lot more purple with the water sample and hard to compare the color range to the color indicator. That said, I feel better about it now with the FAS-DPD giving me confidence.
Ok, so here's my question. I have tested CYA 3 times. The first time I ever did the test I had low confidence in the process, but came up with "55". So I guess that means 60. A couple days later I took it to the pool store and they said it was 30. Honestly, I wasn't super confident in their test either, as another person behind the counter was correcting her interpretation of the CH levels. Ok fine. I have a range at least.
Two weeks later I lose about 1000 gallons after leaving the cleaner out of the water. Oops (lesson learned, will always unhook). I tested CYA again as a kind of controlled test, and came up with 35, but I'll call that 40. Now, I did get that number by shooting my phone light upwards in the tube. Had I not had the light, the number might've been higher. Note, I just discovered these instructions CYA Testing - Further Reading but only before I wrote this post.
So long story short, no matter how you slice and dice it, my CYA is likely lower than the recommendation for an SWG. However... I have been struggling a bit to keep FC down! I am in the Sacramento area, and the pool has >5 hours of direct sunlight, and temperatures range from 85-100 right now. I am surrounded by dozens of redwoods, but all are >30 feet away. Pool and spa are 20k gallons, and I have an IC40 with pump running about 11 hours a day. I have finally got chlorine lower by setting the SWG between 15% and 30%... finally settling on about 25%. This morning's CH reading is 3.4 using the FAS-DPD test. 3 days ago my CH was 4.0 and IC40 was set to 30% before I lost 1000 gallons.
My pool math would suggest I should lose about 1.5-2 PPM of chlorine a day, and should be running my pump about 50%. Pool seems to hold chlorine just fine, and I also have a Pentair BioShield. I now know the recommendation here about UV, but I have it and I'll assume it does something.
-- ok so... my question (finally)... what purpose would bumping CYA up be to say 60-70, if water is clear at FC PPM of 3.0 (or less), and I don't seem to be burning through FC. Are there other reasons? Assuming my tests is reasonably accurate, is there any risk of leaving CYA at 30-50, if I want to keep FC down 2.5-3.0 and this seems to be working? Will I just be surprised eventually with an overnight bloom of something, even with the bioshield as a kind of backup/complement?
