If you are doing a fish only kind of tank, ozone sterilization will break down anything (as an oxidizer) you need to be worried about. Most big facilities do it this way - fresh and saltwater systems. I hate additives and chemical crap that stores try to sell you. Not worth it, don't use, never had a problem. Granted, I've only done this personally up to 500,000 gallons, but I know GA Aq does the same thing on Ocean Voyager... so that has to say someting right?
Also works to clean up a 'poor' water source. At the aquarium here, we use bay water - and it's chemistry is worse than the water you guys will get after doing a gravel vac. After a good hit of O3, it's crystal clear and almost perfect chemistry-wise for our newest display.