and yes 15L.

even when i flush mine only ever manage to get 12L in max tho :\

and yes, deminerialised water.

supermarkets will sell it, for all the ladies here, you put it in irons

different brands of coolant are different concentrates, the most common is that for 1 part coolant you need 2 parts water (on comodores it's 1 to 1 ratio but).
I'm seen a Tecktoloy (I can't remember how the bradn is spelt) one that's a 500ml bottle and makes 10L's or something extreme like that but! in other words, read the label on the bottle and it shouuld tell you!
I think thee falcoooon system is around 14litres, i usually tip thee entire 5 L bottlle in and then just add water till full.
Or you can buy pre-mixed, and jjust aadd it till it's fulll.
I use deminerised waterr, it's onlyy like $2.00 for 5L. So I'd grab two of them so that you know you have enough.
Perosnally I run the Repco Colour Changing Coolant (it's a purple/piink colour and changes to yellow when it's old/needss to be changed).

As long as the coolant has corrosion inhibiters distilled water isnt necessary.
Although if your tap water is particulary 'dirty' then it would be a good idea.

After u flush the system try dropping the drain bung out of the radiator. You have to remove the bottom splash shield to get to it, but its there...

cool so putting in the 5ltrs of concentrate then filling the rest with water cant hurt?? that sounds nice and easy

Follow the instructions on the bottle. If you make it too strong some coolants can ruin rubber seals. If too weak, will be ineffective.