ORP high with and without ozone

[servus]

Added a 200mg Ozotech generator to a Milwakee MC510 controller with ORP probe, about 5 weeks ago.

Here's the timeline:
- week 1: start ORP 200, generator setting 2 (out of 10), running with the skimmer 10h/day, controller set for 300
- week 2: ORP went up to 300
- week 3: ORP went up to 400 (ozone generator not triggered)
- week 4: ORP went up to 450 (ozone generator not triggered)
- week 5: ORP stays around 450 (ozone generator not triggered)

I am concerned at this point, read the other threads, will soak the probe in vinegar and see where it gets me.

 

[Miami Reef]

Take 2 cups of water: one with bleach and one with tank water.

Swirl the probe in the bleach for a few seconds, then swirl it in the tank water.

In a few days you should get normal ORP readings.

 

[servus]

Set up controller for slightly 450, ozone generator started, three hours later ORP at 430. Did not dip the probe yet.

 

[nim6us]

@servus how did this work out for you?

I'm facing a similar problem. I'm using an Apex ORP probe, and injecting ozone into my skimmer 1 hour a night. The ORP has steadily climbed over the past 3 weeks starting at 250, with the tank now sitting at 400+. I haven't used ozone in 6 days and it's naturally still climbing on its own.

 

[Randy Holmes-Farley Verified Community Expert]

Without ozone or other highly oxidizing chemicals being dosed, ORP will never be too high.

Try cleaning the probe. Algae growing on an ORP probe can raise the ORP.

 

[nim6us]

@Randy Holmes-Farley while I've got you.. I was curious if that's possible, can injecting ozone 1 hour a night cause the overall tank ORP to rise cumulatively? Or when you're injecting ozone is the expected behavior that you would see a spike in ORP while dosing and then it would naturally drop back down fairly quickly.

There are so many people reporting wild inaccuracies or drift with their ORP probe readings, then couple that with the difficulty in calibrating, I guess I'm trying to gauge what the actual value is in relation to using ozone.

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley while I've got you.. I was curious if that's possible, can injecting ozone 1 hour a night cause the overall tank ORP to rise cumulatively? Or when you're injecting ozone is the expected behavior that you would see a spike in ORP while dosing and then it would naturally drop back down fairly quickly.

There are so many people reporting wild inaccuracies or drift with their ORP probe readings, then couple that with the difficulty in calibrating, I guess I'm trying to gauge what the actual value is in relation to using ozone.

The normal result is rising ORP when dosing only.

Note that ORP also rises as pH falls, in case that may relate to any results you have observed.