Cross checking my ICO caught a bad reagent bottle

Started by Priya Raman · · 1 reply
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#1
Small one but saved me a headache. FC on the Taylor kit read 2.0 three days running even though I'd been dosing normally, meanwhile the Ondilo kept saying mid 4s the whole time. Figured the sensor was drifting so I almost ignored it, but the gap held steady instead of wandering so I got suspicious of my own test instead.

Opened a new FAS-DPD bottle and retested, got 4.5, matched the ICO right away. Old bottle was maybe eight months open, probably just degraded. Lesson for me is when two sources disagree consistently rather than randomly, check the reagent before you chase the pool. Logged it so next season I'll know to replace that bottle before it gets stale, not after.

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#2
good catch, that consistent-gap-vs-random-drift thing is a smart way to tell reagent issues from sensor issues, never thought of it that way but makes sense.

my k-2006 drops came from a bottle that was maybe a year old and i started noticing my FC readings creeping weirdly low compared to how much chlorine i knew i'd dumped in, took me way longer than three days to even question the reagent instead of just assuming i miscounted my dosing. dropper bottles probably degrade faster than people think sitting in a hot garage, mine lives on a shelf in the garage in phoenix so probably not helping. gonna start dating mine when i open a new one so i'm not guessing at eight months later.