Coolant water brownish

I flush my coolant water very month. Thereafte top up with fresh water agan. Why is the coolant water always turn brownish....
Forum for the Honda Civic EG 1992-1995
http://www.civic-eg.com/forum/
si-b16 wrote:Sounds like you have a rusty radiator...
Get a radiator clean/flush from a radiator specialist
btw what coolant are you using