Weird question...
Our pool was inspected last August when we bought our house. The inspector told me the pool holds 29K gallons, and I've based my chemistry on that number. However...
I was having an algae problem. Had been SLAMing, ran out of bleach, missed a day or two, and the problem got worse. I checked my numbers last night:
FC 12.5
CC 0.5
CYA 50
pH 7.7
Frustrated by this persistent algae problem, I decided to target mustard algae shock level of 29. I added 9 jugs (121 oz each) of 6% bleach.
To my surprise and amazement, I woke up to fairly clear water. The green tint was gone. The chlorine had done its job overnight. I checked my numbers again this morning:
FC 32
CC 0.5
CYA 50
TA 80
pH 8.3
This confused me...
According to Pool Math, adding 1089 oz of 6% bleach would have increased the PPM in a 29K gallon pool by 18. So, last night, before any algae killing, FC should have been 12.5 + 18 = 30.5. My understanding is that the FC turns in to CC as it kills algae. If I ended up with FC 32 this morning, it stands to reason that FC was (a lot?) higher than 32 last night...?
To me, this means one of two things:
1. My pool is not actually 29K gallons
2. I have a water circulation problem
I'm ruling out #2 because ALL the algae in the pool was gone this morning. Last night, the water was green, and I could barely see the vacuum in the deep end (8').
So...how sensible is it to back into pool volume based on water chemistry math? Using Pool Math backwards, it would seem I have a 26K gallon pool, based on the fact that FC went up 20 vs. the expected 18 (not even including FC that was used up overnight). FYI, pool is 20x40 Grecian, with a 2.5' shallow end and ~8' deep end. Pool is 1/3 shallow end, 1/3 slope, and 1/3 deep end. I'd really like to get this right so that I can do a better job managing water chemistry and potentially save some money if the pool is smaller than I thought.
Also, in the history of my testing my water with the TF-100, I've NEVER had CC above 0.5. Like I said above, the water went from green to almost clear overnight. I tested the water early this morning, before the sun was hitting the pool. Why wasn't my CC higher, given that the chlorine did so much algae killing overnight?
Thanks!
Our pool was inspected last August when we bought our house. The inspector told me the pool holds 29K gallons, and I've based my chemistry on that number. However...
I was having an algae problem. Had been SLAMing, ran out of bleach, missed a day or two, and the problem got worse. I checked my numbers last night:
FC 12.5
CC 0.5
CYA 50
pH 7.7
Frustrated by this persistent algae problem, I decided to target mustard algae shock level of 29. I added 9 jugs (121 oz each) of 6% bleach.
To my surprise and amazement, I woke up to fairly clear water. The green tint was gone. The chlorine had done its job overnight. I checked my numbers again this morning:
FC 32
CC 0.5
CYA 50
TA 80
pH 8.3
This confused me...
According to Pool Math, adding 1089 oz of 6% bleach would have increased the PPM in a 29K gallon pool by 18. So, last night, before any algae killing, FC should have been 12.5 + 18 = 30.5. My understanding is that the FC turns in to CC as it kills algae. If I ended up with FC 32 this morning, it stands to reason that FC was (a lot?) higher than 32 last night...?
To me, this means one of two things:
1. My pool is not actually 29K gallons
2. I have a water circulation problem
I'm ruling out #2 because ALL the algae in the pool was gone this morning. Last night, the water was green, and I could barely see the vacuum in the deep end (8').
So...how sensible is it to back into pool volume based on water chemistry math? Using Pool Math backwards, it would seem I have a 26K gallon pool, based on the fact that FC went up 20 vs. the expected 18 (not even including FC that was used up overnight). FYI, pool is 20x40 Grecian, with a 2.5' shallow end and ~8' deep end. Pool is 1/3 shallow end, 1/3 slope, and 1/3 deep end. I'd really like to get this right so that I can do a better job managing water chemistry and potentially save some money if the pool is smaller than I thought.
Also, in the history of my testing my water with the TF-100, I've NEVER had CC above 0.5. Like I said above, the water went from green to almost clear overnight. I tested the water early this morning, before the sun was hitting the pool. Why wasn't my CC higher, given that the chlorine did so much algae killing overnight?
Thanks!
