i jus changed my lim gaskets. I drained my antifreeze, now when i went to refill it i was told it should take almost three gallons. I filled the rad with a gallon of antifreeze and when i was in the store i grabbed the wrong stuff meant to grab 50/50 but actually got conventional. so i was told by a mechanic i could dumb my gallon of water in the reserve area and it would mix its self. But the reserve isnt pulling any of the water into the rad when the car is running it hasnt went down much at all and i let it run for 3 to 5 minutes. My question is will it pull the water and mix without harming anything?