When slamming (which I've had to do twice this season - once to open, and once just this week when CC went > 1PPM), I use LOTS of R-0871, since at [e.g.] 25PPM FC, I need 50 drops of R-0871, potentially 3 or 4 times per day (morning test, 2 tests thru the day, and 1 evening test for my OCLT). This is at 0.5PPM/drop based on a 10ml sample. Is is reasonable to go with a 5 ml sample to yield a 1PPM/drop to reduce the amount of R-0871 I use? I would only use this during the day as the morning and evening OCLT samples need to be very accurate.
FAS-DPD 1PPM test?
- Thread starter tlj3071
- Start date
Welcome to TFP!
Yes, during the SLAM Process you can use a 5 ml test as the margin of error it introduces is not a big deal during the SLAM proper. And you are absolutely correct that you want to go back to the 10 ml test when doing an OCLT. Your reasoning is spot-on!
Yes, during the SLAM Process you can use a 5 ml test as the margin of error it introduces is not a big deal during the SLAM proper. And you are absolutely correct that you want to go back to the 10 ml test when doing an OCLT. Your reasoning is spot-on!
- Jul 21, 2013
- 53,509
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
You can try it. You give up some accuracy but at 25 ppm a 5 ml test will give you an idea where you are.
Test the same water at 10 ml and 5 ml and see how close they get.
Test the same water at 10 ml and 5 ml and see how close they get.
Had to wait 'till this morning to get more R-0871, but here's the results:
FC = 18 (@0.5ppm/drop using a 10ml sample) vs 20 (@1ppm using a 5ml sample)
I tried to keep the bottom of the meniscus on the line in both cases. (I don't know how accurate either mark actually is, and might try figuring that out using a 1ml vet syringe). But I think this is close enough to use for non-OCLT measurements during SLAMing.
Just for completeness, here's the remainder of the water chemistry as tested this morning:
CC = <0.5
pH ~= 7.5 (I'll have to wait for FC to go down some to get a more accurate measurement)
TA = 100
CH = 110
CYA = 70
NaCl = 3000
FC = 18 (@0.5ppm/drop using a 10ml sample) vs 20 (@1ppm using a 5ml sample)
I tried to keep the bottom of the meniscus on the line in both cases. (I don't know how accurate either mark actually is, and might try figuring that out using a 1ml vet syringe). But I think this is close enough to use for non-OCLT measurements during SLAMing.
Just for completeness, here's the remainder of the water chemistry as tested this morning:
CC = <0.5
pH ~= 7.5 (I'll have to wait for FC to go down some to get a more accurate measurement)
TA = 100
CH = 110
CYA = 70
NaCl = 3000
P.S. I found TFP about 2 years ago while trying to figure out how to decrease TA without also reducing pH. This is the ONLY resource I found that had the answer - aeration. I've been a convert ever since. My water has never looked better, and I've saved LOTS of $ that would have gone into less-than-useless chemicals at the pool store.
- May 3, 2014
- 58,767
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
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