Coolant has anti-"most-things-green" chemicals in it (get a coolant leak
on a car and the moss on the pavement will vanish pretty much overnight).
Redline Water Wetter is easily available in the UK.
If you mix Water Wetter & Coolant, particularly with dissimilar metals
in the system, then you can get some copper-compounds displaced out.
This will be a brown sludge, altho more noticeable on cars re bigger
system frequently with multiple dissimilar metals & large liquid volume.
You do not need much coolant.
If really bothered about colour, it can vary in colour with blue, purple
and green commonly available - purple is the propylene based stuff IIRC.
--
Dorothy Bradbury
www.stores.ebay.co.uk/panaflofan for fans, books & other items
http://homepage.ntlworld.com/dorothy...ry/panaflo.htm (Direct)