FC Sample Not Turning Pink

[whats_shakin]

Hi all,
New pool owner here, had our in-ground finished ~8 weeks ago. I've been balancing the chemicals myself using Pool Math, and have had 0 issues so far. ~3 days ago, the samples when using the R870 will no longer turn pink, no matter how much chlorine I add to the pool. Pool is crystal clear. I did leave the reagents outside (in the Taylor test kit box) overnight accidentally when it was warm.

Is there a chance I somehow made the chemicals go inert? My CYA is reading ~50 and pH is in the 7-8pH range (balanced every other day using muriatic acid). I tried a 50-50 mix of tap water and bleach and added R870 to that mixture, and it also did not turn pink at all (I was assuming it would turn bright pink given how much chlorine would be in that test sample...).

5800 gallon gunite pool
50 CYA

 

[Rancho Cost-a-Lotta]

Welcome!
It does sound like the reagent is bad. Usually, when the R-0870 powder reagent goes bad, it turns gray and then black. I would order some more and try out the new stuff. Hang on to the old stuff just in case.

Pool Care Basics

 

[Rocket J Squirrel]

I tried a 50-50 mix of tap water and bleach and added R870 to that mixture, and it also did not turn pink at all (I was assuming it would turn bright pink given how much chlorine would be in that test sample...).

The 50% bleach solution is too strong; it just bleaches out the pink. Remember that test is meant to measure parts per million.

 

[Newdude]

+1. And if your pool water is as high as you think it may be, that may be bleaching out the test. Try diluting the pool water 5:1 and try it again. If it still stays clear, get new reagents.

 

[Leebo]

Have you tried using the OTO test? Just to see if you get any color change?

 

[whats_shakin]

So, just as an update -- turns out I was actually burning through all the chlorine each day (which was surprising to me). I raised the CYA to 60 and increased the FC to ~7 and it's been holding steady. Guess I should have been testing after adding chlorine each day, too, rather than doing it once per day at the same time. Thanks all!