Homemade calibration fluids

[Newreeflady]

Without going to too much trouble i'd like to mix up a couple of homemade pH monitor calibration fluids. I figure this should be easy enough with baking soda, water and vinegar, but my accurate method of testing pH (my monitor) seems to be off and I don't want to rely on one of the cheapo test kits.

So, what i'm asking is if you have recipe for a pH 4 & 7 or pH 10 & 7 soln using these items.

If not, I can mix something up at the lab if you have a procedure. I have acetic acid, etc..., but i'm not feeling like doing titrations, I don't think we have biphthalate, and it'd be easier to just order the stuff online unless someone has a reliable homemade recipe. Anyone?

Best,
Angela

[Boomer]

No we have none :D They are to complicated to make par one Borax mix. We tell people to buy them and even some of the bought ones are way off. Making a calibration solution and to have it remain stable is not an easy task.

A Comparison of pH Calibration Buffers
http://reefkeeping.com/issues/2005-02/rhf/index.htm

But this may guide you if you want the challenge

http://apps3.fao.org/jecfa/additive_specs/docs/t0368e/t0368e14.htm

[J. Montgomery]

<a href=showthread.php?s=&postid=8556630#post8556630 target=_blank>Originally posted</a> by Boomer
Making a calibration solution and to have it remain stable is not an easy task.
I hear that. And then, even if you did make a pH calibration standard, you would need another reliable standard to compare it to as a point of reference. I've never worked in any lab that would even consider that option, even amongst the "old school" guys.

[Boomer]

:D

[Newreeflady]

Ok, got the point;) I will buy more packets of fluid from American Marine I guess.

Best,
Angela

[Randy Holmes-Farley]

I agree.

Happy Reefing. :)