pH meter Calibration

Greetings,
I just purchased a refractometer, which by the way works great, Thanx "Cuttingras".
But.... It also came with a pH tester. The refractometer was calibrated already...but the pH meter either is not, or I am not getting it (the latter is a reasonable belief)... When I check my pH with a test kit it is mild purple which translates to a nice 8.2 / 8.4. But when I use the pH meter it states that it is 6.5
So I assume it needs calibration.
Instructions state to create buffer solution of 6.86 and then immerse and adjust with screwdriver to 6.9 ( I'm assuming I create this solution in a container, which I did..but to come up with reading, I use the test tube)
I did this and it still reads low in the tank (7.1)
test kit still reads 8.2 / 8.4 range.
What do you suggest.
Thanx in advance.

 

Yep, those PH meters fluctuate wildly over time. Think it is that probe gets gummed up...

But I calibrate my PH meter the eassssy way. (and have to do every couple of months)

If my chemical PH test shows 8.2, then that is what set the meter to...:-/

Meter is primarily to let me know of a sudden drastic change in PH...merely a reference, does not have to read exactly.

 

COOL...
Just what I needed to know.
Much thanx.

 

From my experience (that comes from the lab) the most accurate pH indicator is RO water. pH of RO water must be 7.0! Moreover, it is wise to invest in pH calibration buffers for pH 4.0 and 8.5. You can buy these buffers from different brands, and use them to adjust and check your pH meter. Please do remember that pH electrode is far more accurate than colorimetric (lacmus based) chemical tests! If you could afford pH meter get pH calibration buffers!!! Moreover, your pH readout will depend on the temperature! Note that down in your tank-journal! Trust me, I'm almost a doctor

 

pH calibration buffers are different chemical than just pH buffer, such as Seachem reef buffer?
Thanx DOC : )

 

No! In principle you could make your own calibration buffers using Seachem components. However, pre-made buffers are concentrated, so they last longer! Since you spend your $$$ on pH-meter I would invest in buffers! Once you get them store them in dark cold place, the best option is fridge! Moreover, always rinse you pH meter with RO water! Marine salt can hamper the readings and/or/ damage pH electrode!

 

That is clear enough.
Heading out to a LFS today that is going out of Biz. 50% off ....."EVERYTHING" must go kinda thang....doors open at noon PST.....I WILL be first. : )
Thanx again.

 

Good luck...

Let us know what you pick up, if anything.

And if see absolutely mind boggling price markdown on anything you think we might be interested in, let us know...

(Only bother with, if you don't mind making another trip to LFS...;D)

 

I'd ask how are you directed to make a calibration solution and what do you mix it from ? And most solutions I use set to 7.1 and I use a pH. 10 solution also to dial mine in. I test mine once ever 6 to 12 months or unless it just gets crazy and jumping around .. Also temperature will effect it a little . If you got it to 7.1 in the calibration solution then what does it read in the tanks water ?