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Jyetman
04/21/2014, 10:46 PM
Recalibrated my 1 month old apex ph probe lab grade. My tank was showing 8.02 before now with new 7 and 10 solution paks I get 7.85 but my two api test kits are showing 8.1 is this ok? Also when I put the probe back in the 10 solution to test it reads 9.99 is this ok or should I get 10.01?

magnoliarichj
04/21/2014, 10:47 PM
That's fine but probes do age. Also make sure the probe has water flow near it

kurt_n
04/22/2014, 08:58 AM
Recalibrated my 1 month old apex ph probe lab grade. My tank was showing 8.02 before now with new 7 and 10 solution paks I get 7.85 but my two api test kits are showing 8.1 is this ok? Also when I put the probe back in the 10 solution to test it reads 9.99 is this ok or should I get 10.01?

I'd trust the probe over a test kit every time. Way fewer things to mess up. Especially if the probe was just calibrated. Best thing to do after calibrating is stick the probe back in the 7 and 10 solutions. It should read 7 and 10... more or less. If it doesn't, something went wrong with the calibration and you should do it again.

I wouldn't be worried about the 9.99 reading in the 10.01 solution. Close enough for us. Did you put it back in the 7.0 solution also?

Jyetman
04/22/2014, 10:41 AM
Yes it always reads close to 7 and since calibration last night before the lights came back on the probe slowly raised from 7.85 to 8.02 in just 10 hours. Is this normal calibration behavior?

rynoe
04/22/2014, 11:37 AM
Flucuation in PH is normall. Mid day i'm at around 8.12 and 7.9 at night.

Reefvet
04/22/2014, 11:55 AM
Recalibrated my 1 month old apex ph probe lab grade. My tank was showing 8.02 before now with new 7 and 10 solution paks I get 7.85 but my two api test kits are showing 8.1 is this ok? Also when I put the probe back in the 10 solution to test it reads 9.99 is this ok or should I get 10.01?

pH test kits are the last thing you want to reply on. They are far from accurate with the best effort.

When calibrating the Apex it's always a good idea to go back and check the solutions once you've done the calibration. To be within .002 is just fine.

The probe will be accurate for a month or two, depending on where you place it in your system. You should plan to clean and re-calibrate at least every couple of months.

Reefvet
04/22/2014, 11:58 AM
Yes it always reads close to 7 and since calibration last night before the lights came back on the probe slowly raised from 7.85 to 8.02 in just 10 hours. Is this normal calibration behavior?

That's not a fluctuation in calibration.