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Pinpoint pH monitor/probe - not trusting calibration


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#1
NanoTopia

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So I decided to calibrate my pinpoint pH monitor again (it had been 6 months). I did a two part test pH 10 and pH 7 using pinpoint sealed calibration liquid. I was methodical with the calibration procedure as always. After calibration my tank water reads pH 7.9, it was always higher than that, pH 8.1-8.3. I dose Brightwell's Alkalin8.3-P for alkalinity and haven't noticed anything abnormal with my reef. I am keeping my ALK around 10 dKh.

I decided to check my pH with a Hagen colorimetric kit I had on hand, it read 8.3 (ish), where it should be. However, I am not really trusting the colorimetric test either as it is a year old and well..it's made by Hagen.

So, I am wondering if anyone has had issues with the pinpoint pH monitor/probe, could it be the calibration liquid, or malfunctioning monitor/probe? I used to use a pinpoint temp monitor but but stopped using it when I discovered it was out of calibration by 0.5 F (no way to calibrate it).

I guess I am off to the LFS to buy another pH kit, maybe Elos for a third opinion. I would be interested to know however, if anyone has had problems with this unit and calibration or any other thoughts.

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#2
Deckoz2302

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How long did you wait for it to stabilize while it was calibrating in each solution. Did you rinse the probe in rodi before and after each solution?

Edited by Deckoz2302, 14 March 2012 - 08:08 PM.


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#3
NanoTopia

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Probe was in each solution for about 3 minute each. Probe was rinsed between solutions. Numbers were stabilized for quite a while.

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"Problem solving in reef aquaria should be a process of elimination"

 

"Every good reefer reads a lot but thinks for themselves"


#4
jfarabaugh

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I used to worry about PH and would go through the trouble of trying to calibrate it. Best thing I ever did was throw it away and focus on correct and stable parameters through dosing. That was over a year ago.
This is unless you are running a calcium reactor or you are kalk dosing... I do not use either but I think you want to run a PH monitor in those cases.

my .02

Edited by jfarabaugh, 15 March 2012 - 04:32 AM.


#5
NanoTopia

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I used to worry about PH and would go through the trouble of trying to calibrate it. Best thing I ever did was throw it away and focus on correct and stable parameters through dosing. That was over a year ago.
This is unless you are running a calcium reactor or you are kalk dosing... I do not use either but I think you want to run a PH monitor in those cases.

my .02


I agree with the stabilization aspect, but I spent $100 on a tool that is useless if I can't trust the reading it gives. I would like (for peace of mind) to know where my parameters are at. I am a nurse and rely on labs in my profession, this will eat me up if I don't resolve it. I think I will try another calibration using new calibration fluid and buy a colorimetric test kit and check it that way also.

I do wonder how many times reefers react to false readings that result in messing their tanks up. I need testing equipment that works and is accurate or I see not point to own test kits at all. Before I react to a pH reading of 7.9, I need to know it is really 7.9. I would like my pH to be in NSW value (8.3). Just the way I am with things.

14052397019_489f94d8ac_t.jpg  14235742521_7d3ba586db_t.jpg 14711928706_5db25cd919_t.jpg14224634446_e612ccc6c0_t.jpg  12805955343_1481360021_t.jpg   12805957613_d2c95dee49_t.jpg  12805953643_8efd4b306b_t.jpg
 
 

"Problem solving in reef aquaria should be a process of elimination"

 

"Every good reefer reads a lot but thinks for themselves"