I'm not sure how these units work but when an Ozone generator was used where I used to work the smell wasn't pleasant. It similar to a UV steriliser in the job it does, but it functions in a different way.
Hmmm...I notice it doesn't seem to get rid of nitrate, so you'd be just as well sticking with a conventional filter.
As for not water changing for 150 days, pffttt; even if you didnt need to change water because of the nitrate, you'd still need to change water to replenish all the trace minerals etc that your plants and fish would use up.
It's just that most of us have seen loads of different gadgets and potions that claim this or that over our years of fishkeeping.
Nearly every single one has failed to prove itself over time, and nothing has yet beaten a properly cycled filter, coupled with large, regular water changes using a dechlorinator (now there's a potion I'm eternally grateful for!).
Carbon isn't Carbon Dioxide though...It claims that the two Oxygen atoms released from the two Ozone molecules decaying will bond with Carbon to form Carbon Dioxide, which using your theory will benefit algal growth, but Carbon Dioxide doesn't cause algae, it sustains it as photosynthesis can occur.