Kelvyn,

Unless I am totally wrong - Sulphate of Potash is K20 + S, however, the S is
in the form of Sulphate so what you have is actually K2SO4....

Anyway - I have just found a lab chemical outlet in UK called AvonChem
(based in Macclesfield) - if its any good (and I will check tomorrow) then I
am buying the chemicals direct - it works out at about 5.85 per kg for each
one that I want (KNO3 and K2SO4) - that should be ample for 4 years of
dosing - lol.

I have now got all the maths that I need if anyone else wants it in digest
form let me know and I will post it. Have obtained it from other sites -
hope its all OK.

Martin

"Kelvyn Shaw" wrote in message
...
I use the four fertilisers from gemgardening

1. sulphate of potash (K2O)
2. Nitrate of soda (NaNO3, sodium nitrate)
3. Superphosphate (P2O5, phosphorus pentoxide)
4. Garden Lime (CaO, Calcium Oxide). This when mixed with water becomes
Ca(HO)2 calcium hydroxide, which then combines with CO2 in the water to
form
CaCO3 Calcium carbonate which increase my KH and GH.

Ideally I would like some K2SO4 and KNO3 and also micro nutrients without
any iron. But in the UK its impossable.