My take..In my construction career, I rigged equipment in to many water processing facilities, including hospitals. I saw a lot of nifty equipment,but..we're talking fish here, not surgery...they come with tons of their own bacteria, so I think this is trying to compare apples and oranges again....I use many RO/DI's, and also use other forms of water in raising my fish..no sterilizers here, as the size necessary, and frequency of bulb replacemnts and costs are for hospitals, not hobbyists..If bacteria freak you out, then back up a step, and just boil the stuff...JME, 'do what you like' (copyright, Blind Faith)...Gary