Whats interesting is that if you use straight coolant, your car will over heat. It takes water to make it work to cool. Actually straight water is best to use if you don't ever have cold weather, it's just that water by itself will corrode pumps, radiators and all that good stuff. Personally, if you live in a hot area, I'd use a mixture of 70/30 water to coolant and add a bottle of water wetter. You should be set then. I would NEVER go past a 50/50 mix, unless it literally snows 6 months out of the year.
I don't know the amount you need, just make a mixture and fill it up.