On Mon, 20 Apr 2009 01:46:57 EDT, ~ jan wrote:
http://www.hammockkoifarm.com/koi-care-products.html
Is the salt meter I use. I see they have a pH meter, I thought those had to
be calibrated? Hmm..... ~ jan

On Sat, 25 Apr 2009 10:47:55 EDT, wrote:

easy to calibrate. vinegar and baking soda in water have pretty constant pH.
also, soak shredded red cabbage in 50oC water for 1/2 hour makes pretty good pH
solution. http://weloveteaching.com/0spring/0l...lab-water.html

It's not that hard. I got a bunch of pH packets with the meter
(ph3,7,9) so's you could check the whole range. I did for awhile,
found it didn't change much, and so only checked mid-range. That
didn't change much either, so now I "calibrate" rather rarely. I
suppose it might be important if you were trying to keep pH to two
decimal places or something, but generally with plants I'm mostly
concerned with only one digit and maybe (on occasion) I pay attention
to the first decimal, rarely the second. I've had an electric digital
pH gauge for over a year now and find it a lot easier (and probably
more accurate) than anything else.