Here is a formula for Knudson's formula C
Leave out the agar to make a liquid. I am away from home will try to look up V&W this weekend when I get home.
Calcium Nitrate 1.00g
Potassium phosphate 0.25g
Magnesium sulphate 0.25g
Ammonium sulphate 0.50g
Ferrous sulphate 0.025g
Manganese sulphate 0.0075g
Sucrose ( sugar) 20.0g
Agar 18.0g
Distilled water 1000mL
Originally cited by Clements, 1982. Australian native orchids. In Orchid biology II, ed. J. Arditti, pp. 295-303. Ithaca, New York: Cornell University press.
Ca3(PO4)2 200 mg
KH2PO4 250 mg
KNO3 525 mg
MgSO4 * 7 H2O 250 mg
(NH4)2SO4 500 mg
Ferric tartrate 28 mg
MnSO4 * 4 H2O 7.5 mg
Sucrose 20 g
Agar 8 g
This is for 1 liter.
Leave out the agar for liquid.