Well I'm beginning to set things up for my octo tank, it's a 125 gal. I'm going to build a refugium sump with a protein skimmer for filtration. I work at a pharma company and maintain our purified water system. The system consists of a softener, DI unit, RO unit, and then water in the tank is ozonated, before water goes to useage points the ozone is removed via UV light. TOC (total organic carbon) is way down around 1.07 or so. It's really pure water devoid of most anything. When steel comes into contact with it it corrodes (rusts) quickly. Sooooo finally my question, is this water too pure to use for my aquarium? I know it won't be that pure for long once salt is added and bios build. I have a pretty limitless supply, so it would be great if I could. What do you think?