using car radiators...why not?

[Alexontherocks]

I will look into having an impeller made out of copper; I just will have difficulty finding anyone willing to make one for a very reasonable price.

Regarding anticorrosives I gather that

1) the optimal ratio is 1:10

2) antifreeze designed to avoid cavitation and galvanic corrosion is preferable thus something like G12 could do

3) there is still a minor issue: I would like to add UV additives to the mixture but anything other than red will react negatively in terms of end result. I was hoping for green but it seems that being forced to use a red anticorrosion agent I would eventually end up with something dark purple. Isn't there an alternative to G12 that looks more blu/green? (this is not important but it would look very good in the end)

thanks!