pH testing

scout

New Member
I am new to the hobby. Just started a 29 gallon Oceanic Biocube around January 1 of this year. Things are going fairly well and I have certainly learned alot by reading these forums daily. Unfortunately I did not find this site until I was up and running or would have done a couple of things differently , but again all seems to be working out ok.
One area I am trying to improve is the quality of my testing. Dropped the multitest strip and the hydrometer and have gotten some Salifert test kits(about to order more) and the refractometer from this site.
I am trying to get an accurate pH value. I bought the pH meter from this site recently but have not calibrated it yet, because it requires a couple of "known" pH values and I did not know where to get those. I have found, through a search on this site, how to get those samples. But I did get frustrated because I can not find the name of the manufacturer of this meter on this site or anywhere on the meter or with its limited instructions. I had wanted to contact them about where to get the solution, but just couldn't find out who makes it. It is probably right there in front of me but again just couldn't find it.
Anyway, that got me to wondering about the quality of the meter. In my search for the "known" solutions I saw where people used some other brands but did not find any comment on this one. Does anyone have any experience with it? It was cheaper than some others that I later found, which made me a little nervous too.
Is a pH meter even necessary? In reading it seems as though an abnormal pH is not something to be treated in and of itself, but a sign of another problem. Would it be ok to just moniter the other parameters with high end test kits and follow the pH with something like a Salifert pH test kit instead of an actual meter which has to be recalibrated periodically? Just wanted to get some thoughts on which direction I should go.
Well the first post was a long one. Will try not to let it happen again. But again I appreciate any help.
 
I bought the same meter and am also looking for an easy (cheap) way to check the calibration. I have heard RODI water is some PH. The meter seams to jump around quite a bit, to the point that you don't want to believe it.
I can check the water in the tank, then rinse it in RODI, and then test it again and the reading will be different by .5 or more.
Questions for other people that have a hand held meter.
What is the PH of RODI water? :notsure:
How long to you have to hold the meter in the water to get a stable reading?
Do you hold the meter in one place or sworl it around(I get differnet readings both ways)?

Is there a cheap way to verify the readings?
Thanks :help:
 

bang guy

Moderator
Originally Posted by NewBostonConst
What is the PH of RODI water? :notsure:
Pure water will have a PH of 7 but mathematically it has no PH.
The problem with testing RO/DI is that it will readily put anything into solution. This means that as soon as it is exposed to air CO2 will immediately dissolve into it and this will drop the PH fast, really fast. As a result there's no reason to test the PH of RO/DI water because the PH will just tell you that CO2 made it into the water, nothing else.
To calibrate the meter why not just test tank water with a test kit and then adjust the meter to match?
 

zman1

Active Member
If your trying to calibrate a pH monitor, why not order calibration fluid. If the reading doesn't stabilize after a few seconds, that is a symptom that the probe needs to be replaced. Temp. plays a roll on calibration as well.
Google"PINPOINT pH" you will find a bunch of places that sell it.

 
The Meter is brand new. I don't trust my PH kit, that is why I bought the meter.
How many other people calibrate there meter?
Anyone else that has this meter does it act the same?
Thanks for your help.
 

gwh57

Member
Originally Posted by NewBostonConst
The Meter is brand new. I don't trust my PH kit, that is why I bought the meter.
How many other people calibrate there meter?
Anyone else that has this meter does it act the same?
Thanks for your help.
I use the above calibration fluid with mine. That is what it is for.
 

geridoc

Well-Known Member
No pH meters are "set it and forget it". All need frequent calibration. In our laboratory we run a two point calibration every time we do a pH determination. If the reading is not steady it is time to either replace the probe or do a service on it, depending on the type of probe.
 
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