Measurment Errors

[Mindi]

For at least 12 months I have been chasing low pH with various approaches including scrubbing (good, easy,but expensive), external air to skimmer ( very minor improvement) NaOH based Alkalinity treatment replacing Bicarbonate of Soda.... (surprisingly small effect) still measuring 7.9 middle of the day on my "calibrated" green pH meter.
Decided it was time to replace the meter as it was taking longer and longer to stabilise and the model concerned does not have replaceable electrode. Went to Hanna and bought a more accurate (+/- 0.1) meter with Hanna calibration fluid. After careful calibration I have measured my midday pH at 8.2-8.3 for 3 days in a row.... recalibrated and same result....

So I have almost certainly been chasing a wrong measurement all this time. It's an easy trap to fall into.

 

[Dr. Reef Verified Sponsor]

Been there done that. I had a nitrate kit that had o expiration date on it. I had been using it to measure nitrates. Well it always showed nitrates to be 0-5 PPM. When I got close to finishing up the bottle I ordered a different brand and came to find out that my nitrates were not 0 or 5 and more like 25 PPM and I double checked by ordering it another two new kits so I have 3 kids total and they all match except for this one. Got rid of it quick

 

[Randy Holmes-Farley Verified Community Expert]

Thanks for the reminder to not always accept test results, especially if they seem unusual.