ORP spike after increasing skimmer?

[aaron186]

The ORP on my tank has sat around 200-300 for the past 6 months via Apex and BRS probe. I added the probe with the intention of adding ozone which I just haven’t had the chance to get around to doing (just had a baby). I recently bumped the skimmer air on my dc skimmer up a notch. Since doing that my ORP has spiked to the 500s. The skimmer is tuned a bit better now. Is there any reason to be concerned about this jump in ORP? I cleaned probe but did not calibrate it (seems hard). If my ORP is sitting at 500 does this mean I can’t run ozone? I also have a UV running 24/7. I turned that off in case there was an issue with it causing the spike and it hasn’t changed. I’m pretty sure the change is due to the skimmer setting change as it’s the only thing I changed.

 

[Randy Holmes-Farley Verified Community Expert]

I don’t believe that ORP of 500+ can be accurate without adding oxidizers. I’d suggest first cleaning the probe, and if thst doesn’t bring it in line, try testing a standard ORP fluid.