Orp lowering with ozone

[scotty333]

Guys,
I’ve just bought a Milwaukee mc500 to measure my orp and it’s currently 180 , I switched on the ozone generator (1000mg/h) on 400ltr tank and I’m 20 minutes it dropped to 150
?

 

[scotty333]

I checked the probe with 256mv solution and got 251

 

[Ironwill723]

Same thing happened with me when I first started running ozone. After a few days it slowly started rising again to my set point on the orp monitor

 

[scotty333]

The ozone’s been running 10 days without the controller for 3 hours a night

 

[Randy Holmes-Farley Verified Community Expert]

I’d just keep monitoring. I don’t think there’s a real way ORP actually drops when using ozone, but the probe may take substantial time to equilibrate.

 

[scotty333]

Any experiments I can carry out?
Even the machine being 20 euro ?

 

[scotty333]

orp is steady now at 318

 

[Randy Holmes-Farley Verified Community Expert]

That sounds fine.

 

[scotty333]

Ozone’s running during the small hours so when I check at 9am it’s up about 10mv

 

[Randy Holmes-Farley Verified Community Expert]

Ozone’s running during the small hours so when I check at 9am it’s up about 10mv

That may be from the ozone or the pH decline. A pH lowering raises ORP.

 

[scotty333]

Ah ok boss
It’s still at 318 throughout the day though , ph 8.3

 

[Randy Holmes-Farley Verified Community Expert]

Ah ok boss
It’s still at 318 throughout the day though , ph 8.3

That’s fine.

 

[scotty333]

Cheers boss
I’m hoping when at 400-450 I can stop carbon for clarity purposes I mean

 

[Randy Holmes-Farley Verified Community Expert]

Cheers boss
I’m hoping when at 400-450 I can stop carbon for clarity purposes I mean

Higher ORP is not what leads to clarity, nor is there any evidence that it is desirable.
Ozone and the Reef Aquarium, Part 1: Chemistry and Biochemistry by Randy Holmes-Farley - Reefkeeping.com

Ozone and the Reef Aquarium, Part 2: Equipment and Safety by Randy Holmes-Farley - Reefkeeping.com

Ozone and the Reef Aquarium, Part 3: Changes in a Reef Aquarium upon Initiating Ozone by Randy Holmes-Farley - Reefkeeping.com