Like many people, I monitor ORP through my Apex despite not really believing that ORP is telling me much of value. I don't pay much attention to it other than noticing what the "typical" numbers have been. Over the past few months, my average ORP has averaged around 220 mV. In the last week, that's risen to an average of 279 mV, and is currently sitting above 300 mV. I have recently started using Rowaphos to (successfully) bring down phosphates - could this simply be ORP rising as phosphates are removed from the water column? Is there anything for me to be concerned with rising ORP numbers?
Whenever a parameter changes beyond normal fluctuations, though, I always like to be sure. No ozone dosing here, from what I've read it seems like a lot of money for not a lot of benefit.
