Bad R-0871

SteveK52

Well-known member
Mar 11, 2019
124
Taylors South Carolina
My FC seemed high using the Taylor's drop test so I took a sample to a couple of pool stores to see what their test would show. My testing indicated 7ppm and both pool stores showed 5 ppm. I recently bought replacement reagents for the R-0870 and the R-0871 which were a couple of months over a year old. I have been using the new R-0870 as I had run out of the old. However, I was still using the old R-0871 as there was still some left and everything had been stored in the original case out of the heat and sun. I thought just for the heck of it I would use some of the same water I had used for my test and the pool store test and use the new R-0871. The result was 5ppm instead of 7ppm. This appears to indicate the old reagent was bad. I wonder how long has it been bad and how should I have known?
 

Holydoc

Gold Supporter
Jul 17, 2016
402
Navarre/FL
Not sure if your test was conclusive since water that has sat for a bit will lose its chlorine. A better test would be to test your pool water back-to-back using both the old and then the new. That will give you a better indication of whether your old R-0871 is actually bad or not.

On a side note, I have nearly the same size pool as you. For me there is absolutely no way I can ever have expired R-0871 with my testing routine. I will easily go through a 2 oz bottle of R-0871 in a year. How did you stretch it out for so long?

I would make it a habit (I do) to replace all my testing reagents yearly. That way you never worry about expired ones.
 
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Holydoc

Gold Supporter
Jul 17, 2016
402
Navarre/FL
Thanks for the clarification Steve. That does make you scratch your head. Maybe Texas_Splash and you are on the right track with the tip. However that would be disheartening since if it is the tip, then your measurements have been off since you had the bottle. I am hoping the reagent was passed its expiration. Keep us informed.
 

revitup

Bronze Supporter
Nov 30, 2019
258
Pawleys Island, SC
I have always suspected that there is considerable variability in the tips bottle-to-bottle. Swap the tips and test. I did at one point and found that the results varied.
 

TO116

Well-known member
Jun 30, 2019
67
New Jersey
I have two bottles of R-0871, one from the Taylor kit and one from TF Test Kits. They produce different sized drops, resulting in about a 1 ppm variability in results.