and idea how to. like would a air freshener spray cause harm if i spray them on my plants during flowering. or what.
The Ona products work great imo, here's a link if you'd like to check them out. Fifth Season Gardening
You need to go get the new Glade for Marijuana, haven't you seen the TV commercials? Don't spray any chemicals onto or around your plants, you'll be smoking that later. The key is that you don't combat an odor by adding more odors, you need to neutralize the odor molecules out of the air. Best way to do that is a carbon filter, you can build one yourself there are several DIY threads on GC...
Get a carbon filter or build one that is your BEST option. Almost everyone has a fan/filter combo at a decient price, no dont use a air purifier.
No. An air purifier draws air in and expels air out into the same space -- in this case it would be your grow space. You should have air ventilation through your grow space, so you would be mixing the cleansed air with odorous air out the exhaust, before it all goes through the purifier. The odor of flowering MJ would overwhelm an air purifier anyway. You want the same principle but in a closed system, where you are channeling all of the exhaust through the filter. You want an air-sealed grow space with fresh intake, exhaust to get rid of heat and smell (and to draw in the fresh air), and then you pump that air through a carbon filter. That is essentially what a lot of air purifiers are, carbon filters. You basically need to build your own air purifier, with your grow space built in.