Quote Originally Posted by Holst View Post
The nickel blocks should be pretty resistant to corrosion.

If you use that Hydrx additive then it should act as a biocide to stop anything growing.

Personally I would still go with plain water and green UV tube.
hydrx is crud mate, From all the hype it had i gave it a go in a few old loops and nothing but gunk after months.. Still distilled+pt nuke+silvercoil imo is the best option..