Well I treat with O3 before I pump the water into my res but not when my plants are in the same room. Ozone is extremely corrosive and is one of the strongest oxidixers known to man. I would be very careful with this one. Ozone is generated as a gas and is pumped in the res...that gas will escape and be exposed to the tops of your plants, not good.

I use H2O2....it raises the dissolved O2 quite a bit over a much longer period of time...Ozone does have its place though.