Never heard of Idofor before...interesting! After reading the info at the link you provided I'm still not sure it's the right product to recommission a fresh water system...'cuz although most people think only in terms of the tank, it's actually the plumbing-- the molds, mildew, fungi and bacteria which thrive in damp dark places when the water pump isn't on---that's the source of most foul funky water. I question whether the concentration of Idofor is strong enough or stays in the plumbing long enough to kill 'em.
So I need to learn a lot more about Idofor before recommending for or against using it instead of bleach to recommission fresh water systems.
Bacterial and wild yeast infections are a big no-no in beer brewing as they can ruin the flavor. I flush my entire system with Iodofor between each brew, including pipes, pumps stainless beer kegs, serving taps, plate chillers etc. The thing I like most compared to bleach, is that it is a no rinse treatment which means once you have drained it out of your system you do not need to rinse, you can just refill . It has no odor, and adds no flavor.
It does not remove scale, so when I notice any buildup in my brewing equipment or serving lines, I use another product called Beer Line Cleaner (BLC) which is a Chelated Sodium Hydroxide Solution (30%).
BLC Beer Line Cleaner
BLC Liquid cleaner for draft system lines, including tubing, faucets, and valves. Make a solution by mixing 1 oz. per gallon of warm water, and pump it into your beer lines. BLC needs 15 minutes of contact time to remove deposits, beer stone, etc. Rinse with clean water.
I use both of these product for stainless and plastic items. I do not use brass in brewing as it adds a nasty flavor when exposed to beer.