Anti Freeze turned brown.

From the schooling i have had for oilfield compressor, i was taught to use deionized water and watch the pH levels to keep the cooling system clean.

If you have access to deionized water it wont leave deposits in your radiator, from what i read it will actually pick up deposits. But if you don't have access i would use filtered water.

Coolant pH below 8.3 pH is not acceptable for use in engines due to its corrosive nature. The correct pH value should be maintained between 9.5 - 10.0 pH. Below 9.0 pH it is advisable to flush the cooling system and refill with a new coolant solution

This is what i am going to follow on my build. Just my 2cents:yawinkle: