Just to confirm, the 3 solutions can all be mixed in advance, but not mixed together in the same container.Really good post... thanks for converting into the "Aussie version", although I have a few questions:

He says that the 3 solutions can all be mixed, but that part 3 is used "Each time you finish adding 3 litres of both parts of Recipe #2, add 240 mL (1 cup) of this stock solution"

As the solutions cannot be mixed together, he is referring to 3 litres of the calc solution and 3 litres of the alk solution.- does he mean 3 litres of the combined part 1 + 2 solutions, or 3 litres of each part 1 and part 2?

As above, they can't be mixed together.- does this mean that if you were to combine all 3 solutions, you mix in the ratio, 1.5L part 1, 1.5L part 2, 0.24L part 3?

As above, they can't be mixed together.- when he quotes the guidline dosage rates, is it 0.2mL/gallon, 0.4mL/gallon, etc... does this mean 0.2mL of the combined solution as per the above ratio? Or does he mean 0.2mL/gallon of the combined part 1 and part 2, and then only add part 3 as decribed (1 cup after 3 litres of both part 1 and 2)?

I am not a chemist but I think you will get nasty reactions if you try and mix these solutions together. Some commercial products do combine the calc and alk parts but I think this is because they have access to purer products which will stay in solution better.

Hope this answers your questions - post again if I havn't.

Cheers