What could cause steady increase of ORP

[cb684]

The probe is not calibrated. But for the last few days ORP is steadily increasing. No ozone or uv in the tank. Fishes appears to be doing well. Anything I should be worried about?
Thanks.
CB.

 

[Randy Holmes-Farley Verified Community Expert]

A probe getting algae on it will do that.

Unless you are using ozone or other oxidizers, there's never any cause for concern over ORP being too high.

I'd carefully clean and/or recalibrate it.

 

[cb684]

Thank you.

 

[Randy Holmes-Farley Verified Community Expert]

You're welcome.

I discuss ORP issues hare:

ORP and the Reef Aquarium - Reefkeeping.com
http://reefkeeping.com/issues/2003-12/rhf/feature/index.htm