Don't have the neg ion air cleaner blow on the plants, they can cause necrosis on the plants in close proximity.
I was doing an experimental grow and had used a Purelite 6400k CFL with a built in ion fountain in a CFL reflector that was close to the plants, it caused massive necrosis from excessive neg ions..
As far as never using ozone, well thats a crock of BS. Ozone can also cause necrosis as can neg ion fountains, but when used properly an ozone generator will remove organic odors and many inorganic odors better than ANYTHING on the market. Better than a sock, better than a carbon scrubber, and surely a hell of a lot better than an ionizer.
Key word above is when used properly. I use my ozone generator on conjunction with a neg ionizer, in conjunction with a carbon scrubber and as a last line of defense, a UVc rod in my A/C ducting
normally I run my ozone generator an adjacent room and not in the grow room itself, although I have before and had no issues.
The key is to use them on a timer, or via a three pronged appliance remote. Usually one only needs to run their ozone generator for a few minutes when the ventilation turns on, and maybe a few minutes every few hours. My Ozone machine also has independent controls so when Ozone is not needed, I run the machine just putting out neg ions with no 03 production.
I've tried most every air cleaner on the market, and anyone that says avoid Ozone, doesn't understand that ozone is the best method possible to eliminate organic odors. Yes they can be harmful if used improperly and can cause mucous membrane problems, but when used properly and not using it as a 24/7 air cleaner, there is nothing better. Many people buy these and turn them on full blast and run them 24/7, creating 500-2000mg/hr of ozone, the EPA safe limit is .05/mg/hr
These are not air cleaners per se, they are air sanitizers that have a benefit of removing all organic odors in the air. If run a few minutes every few hours, they are very effective. A lot more than an Ionizer. Don't get me wrong, Ioniers have their place in the grow world, but lets say someone stops by your house unexpected. If you need to clean the air very quick, you turn the ozone generator on full blast. The odors will go kapoot and nobody will smell the odor of a grow.
Carbon scrubbers and Ionizers cannot do the same. (Carbon scrubbers are a good thing to have though)
In thirty minutes the 03 reverts back to 02. But in every home that has a 03 generator, learn the dangers of it, and use it properly.