citrus wash and gloss dilution for pre wash

I received this product :
Foam Sprayer FoamyClean 100
http://www.gloriagarten.de/en/home-a...clean-100.html

in the introductions says thet need fill the bottle 0.5 litter .

for pre wash , how ml I need fill in 0.5 litter water ?
I don't wont to strip the wax .

thanks