Need advice regarding changing coolant

[johnwk]

tmontague: I changed my coolant today following your instructions, but I added a few steps in the middle on a friend's advice. After draining the old coolant, I filled the system with distilled water and some Prestone Flush+Cleaner. Following the Prestone instructions, I drove for 10 minutes, drained it, filled it with distilled water, drove it, and drained it again. Even on the third drain, it was still very pink. (In total, about 3 gallons of liquid came out.) I ran out of daylight and distilled water, so I just filled everything up with 50/50 and called it a day.

Now I have two questions/concerns: since the third drain was still pink, there must still be some of the original coolant, plus some distilled water. Is that a problem, or is this a "good enough is good enough" scenario? Second, I'm assuming there's still some Prestone Flush+Cleaner in there. Is that okay?

Thanks for your help!