Water flow direction in radiator

As far as I know coolant enters the bottom and discharges to the top and usually :flushing" is simply removing all the old coolant by Flushing until the water is clear ... most coolant is 50/50 anyhow so you adjust acordingly

Thanks guys. I was going to flush but there is no way I could obtain a 50/50 ratio with only getting 5 quarts out of the radiator when the cooling system holds 16 quarts. I was going to remove the bottom hose from the block, but it is in such a god awful location with the compression clamp on top it's hard to get to, but not impossible. I suspect if I can remove the bottom hose from the block, I can get out another 4 quarts (as least), that way I can fill with full strength plug two gallons of distilled water.