Orp

[jose hernandez]

So looking at me apex my orp seeems to be higher with my return pump off than when it’s on is this normal Also is a higher orp beneficial for a reef tank or not

 

[Spare time]

Ignore ORP

 

[Randy Holmes-Farley]

Higher ORP is not "better" than low.

Depending on where the probe is, the effect you are seeing may be real, or electrical interference.

This has more:

ORP and the Reef Aquarium - Reefkeeping.com

 

[jose hernandez]

Probe is in the return section where is a good place to put it

 

[Randy Holmes-Farley]

Probe is in the return section where is a good place to put it

If the skimmer outlet is near it, it might be real, raising the ORP a bit in the sump when the return is off.