Rupert wrote:
"Derek Turner" wrote in message
...
Rupert wrote:

Interesting:- Looks like JI ericaceous is similar to JI seed compost
.The difference is that limestone is replaced with sulphur to give a
higher pH.
I have never used JI but I suppose perhaps I end up making something
vaguely similar by mixing soil with bog standard seed and potting
compost.
Make that a LOWER pH. pH7 = acid pH7 alkaline. p stands for 'minus
logarithm to the base 10', and H the concentration of hydrogen ions (if
you are interested). So the higher the H+ concentration the lower the pH

Woops and me an ex Khemist. Thanks.

Always though pH meant potential for hydrogen?


Google say power or potential but p just means -log(10) and can be
applied to anything AIUI. 0.1 molar salt solution would have a pNa (and
a pCl) of 1. Not very useful and so not used often!

When applied to gasses (pO2) I think it means partial pressure and is
quoted in mmHg, just to confuse things!