CO2 scrubbers and ORP

[ReefHunter006]

Any i ideas why ORP would drop like a brick after adding a scrubber to an air stone instead of a skimmer?

The air stone does flow into the refugium. If that matters.

Edit: I understand the relationship between ph and ORP. This is not that atleast not in the usual sense.. When scrubber is pluggeg into the skimmer ORP fluctuates 250-300. The air stone version has plummeted below 198. Attached ph for same time period.

 

[Reef - Tripp]

Because the ph rises, the orp always moves opposite the orp, if its orp rises the ph will drop

 

[ReefHunter006]

Because the ph rises, the orp always moves opposite the orp, if its orp rises the ph will drop

Ph hasn’t drastically changed. Talking .03 above baseline. ORP doesn’t react this strongly with the scrubber plugged into the skimmer. I’ll update the post to better clarify. I assumed that people would know I understood the relationship. My b.

 

[ReefHunter006]

My corals are showing serious signs of stress and my sticks are pale and showing various spots of bleaching.

I have zero idea what this triggered.

 

[Saltinmyblood]

Mine did the same thing after adding a scrubber.

 

[Randy Holmes-Farley]

Aside from the pH effect (which might be a lot more than you think if the ORP probe is near the skimmer outlet), if you are using a recirculating scrubber (not optimal, IMO), you may be reducing the oxygenation in the water, which may reduce ORP.

Might also be test error/coincidence.

 

[Randy Holmes-Farley]

My corals are showing serious signs of stress and my sticks are pale and showing various spots of bleaching.

I have zero idea what this triggered.

Maybe the lowered ORP is caused by the coral problems (whatever they are), not the coral problems caused by the ORP.

Or maybe both are caused by the same third (unknown) thing.