Ph probe problem

[Netta Fish]

I bought a new pinpoint ph probe to use with an older pinpoint monitor... After two calibrations with 4 and 7 my tank continues to read 7.85. All liquid tests show 8.2 ... Refugium light is kept on 24/7... It's a one 120g reef with great growth and color from coral so I'm not sure what to think.... Any thoughts?

 

[Flipside]

Do you have the probe in a cup with effluent in it? If so, try putting a straw in there and blowing in it. If it changes, recalibrate. If it doesn't, call store and try to get a replacement.

 

[Netta Fish]

Do you have the probe in a cup with effluent in it? If so, try putting a straw in there and blowing in it. If it changes, recalibrate. If it doesn't, call store and try to get a replacement.

Kinda lost....I have it in my tank right now

 

[Flipside]

Take it and put it in a cup with tank water in it. Blow air in it, and the probe should be affected by that. That means the probe is reading something. pH should drop.

You could have a defective probe or very stable pH. That's not surprising with your fuge lighting schedule.

 

[Hudzon]

you should be using 7 10 if only using to samples to calibrate

 

[Flipside]

Didn't even read that. Yes to the above.

 

[Netta Fish]

the probe is working. the ph dropped when bubbles where blown... Just curious what's the diff in calibrating with the ten?

 

[Russellaqua]

When calibrating a pH probe (or any instrument for that matter) the calibration standards or solutions need to be points above and below what you are measuring. Using pH 4 and 7 solution gives you 2 calibration points below the roughly 8.2 you're measuring. Using pH 7 and 10 solutions gives you a point above and a point below your measurement. This helps ensure a more accurate measurement.

 

[Netta Fish]

Thanks ill give that a shot tonight