Geez I wish I had my Profilux now, it will be 8 weeks before I get the new parts for it. I had it working for five days and after correct calibration it was reading 207 for redox. This was after a water change, prior to the water change it was about 268. I was testing my water params and they were zero for nitrate, nitrite and ammonia. When I first calibrated it, it showed 85 and then slowly went up to 207 then to 224. The I had a flood and my Profilux was toast.
The fellow I bought it from said the redox meant how much oxygen was in the water... I didn't know what he meant. I thought I would set up and ask questions about it later...
I did not know if the numbers should be lower or higher but the cleaner my water was, the lower the readings.