If you remember reading this article a few days ago, you will remember that antifreeze/coolant should be mixed 50/50 with clean drinkable water. It sounds pretty easy and it really is, but it can be a little difficult to judge exactly how much fluid you have in your jug if it doesn’t have a clear side. To see exactly where the fluid level is, you can simple take a flashlight (the brighter the better!) and put it over the top of the jug. This handy little trick is not limited to just the use shown in the photo, though. Many brake master cylinders, coolant reservoirs, power steering tanks, etc. have translucent tanks, and this handy trick helps out with them as well.
By the way, the condenser on the bench is a scrap unit. Don’t ever set anything on top of a radiator or A/C condenser; those fins are very fragile!