pH Calibration Fluid for Less than a PENNY!!!

[Reefd Up]

So, my pH probe was dropped...and I had no calibration fluid handy.  ARGH!  What a pain!  I tried seeing if it was anywhere near correct...nope...my water tested at almost 9 pH.  Ugh.  

Fine...so I did some research online to see if I could make my own solution since it was after fish store hours.  If you aren't familiar with it, here are the links:
http://web.archive.org/web/20021015005420/www.animalnetwork.com/fish2/aqfm/2000/feb/bio/default.asp
http://reefkeeping.com/issues/2005-02/rhf/index.php#7

What is boils down to is this...

Mix 1/2 tsp. of Borax (found in the laundry detergent aisle) with 2 cups of water.  Measure the temperature and compare the temperature and your pH probe's value to the chart on the first link.  Then...calibrate!



My pH probe should NOT have been reading 9.7.  It should've read 9.2...so I had to calibrate it.


Seem too easy & cheap?  Nope...not really...it's all explained in the first article.  AWESOME!!!

So yeah, the Borax was $3.99 at Meijer...plus the cost of water.  I can make 1,077 batches of calibration fluid.  Boils down to $0.003.

Hope that saved a few of you some money!

Oh...and if you don't feel like buying 1000+ batches of this...I'll give some away at the meeting.  Goodness knows I'll never use it all unless I use it for laundry!  

Nikki

[TechGuy]

I think half your problem is that "probe". You actually trust that thing? I have the same one.

[Reefd Up]

I think half your problem is that "probe". You actually trust that thing? I have the same one.

Has always calibrated correctly until I dropped it.  The pH probe has to be kept in water, and the electrode will eventually leak out.  Do you still see fluid in the bulb? 

[TechGuy]

Has always calibrated correctly until I dropped it.  The pH probe has to be kept in water, and the electrode will eventually leak out.  Do you still see fluid in the bulb? 

Yeah I keep it capped in water, stored so its wet all the time. Bulb is full. I think mine is just defective. Its weird, sometimes its accurate with a liquid kit, other times its WAY high.

[Reefd Up]

I've heard about half good and half bad on them.  How old are the batteries? 

But yeah, I've had mine about a year...and it's always calibrated right until I dropped it and jarred it all crazy.  I'm really impressed with how cheap and effective the borax solution is to recalibrate.  Everything in the hobby should be that easy!

[cyberwollf]

Have you compared it to real cal fluid to see how close it is?

[Reefd Up]

Yup, I couldn't tell a difference on my probe.  I'm sure all probe vary in sensitivity, but I couldn't tell a difference.  Chances are, it's close enough. 

The original author of the article discusses how accurate it is, but I'm not a chemist, so I won't try to elaborate.