far too much antifreeze in it now! I use a 50/50 mix which is still a bit too much antifreeze for summertime but it works. main reason I go for 50/50 is its easy to measure

chuck a whole bottle in, fill bottle with water chuck that in, then put half the antifreeze from 2nd bottle into 1st bottle and top them both up with water. 50/50 in the tank, and 2 bottles of pre-mixed antifreeze

check out the coolant faq in the garage sections, covers how to bleed the system and check it for leaks.