ORP and Ozone

[Pescador]

My ORP stays at about 325-350 with 200mg running flat out with a 500mg air dryer and an ALS reactor. My controller is set at 350 with a 20-30 drift so it won't go above 375.
But my tank started out at a lower level than yours 200-225. Some tanks can have a higher ORP level without ozone so you will have to keep a closer eye on your controller not to raise it too much.
I would set it 25 above your baseline without ozone but not above 450 and monitor your water clarity from there.