Kill Coil vs liquid Biocide (or both)?

[eTanium]

So, what is better, and in what ways? I have read that the silver in kill coils can have adverse effects with nickel/copper in coolant blocks. Does it also impede flow through the loop?

I've also heard that the liquid Biocides can react with dyes in the coolant (when used), that cause some "clotting" effects.

What is the best system here? Can they be combined?

What are some of the better brands of both?

Thanks.