I understand before refilling your system after a coolant flush you should refill and drain the system several times with water.
This is fine however last time I refilled and drained over three times and there was still colour in the fluid. I don't have the time to keep flushing over and over until it is pure clean because I need the car for work.
I was wondering would it do any harm to flush out most of the fluid but not all and refill to correct 50/50 mixture using a hydrometer?
I would also like to ask from your experiences what is the rough number of times you drain and refill your fluid until it is pure water as maybe I am doing something wrong?