Leftover Coolant

[Basstriz]

In July, I picked up some distilled water and concentrated coolant (I don't even know which one at this point to be honest), and filled the jug I had with it. What I'm wondering is if I can still use that coolant now, after it's been sitting for 6 months, or should I just get some new stuff to use? Like, I'm just concerned that the mixture might have any issues from the tiny amount of plastic it could have worn away inside all this time. But if not, how long would you say I can let this go? 

Thank you in advance!

[RollinLower]

i wouldn;t use coolant older then a year, tough anything before that should be fine. 

be sure to check for any debris that have settled in the coolant tough. if a lot of stuff is floating around in there you probbaly want to get a new jug of distilled water instead