ORP Probe - Readings

cccharliecc · Jan 23, 2018

I just filled my tank about 2-3 days ago, nothing in it put dry rock, live sand and salt at this point. Just started Dr. Tim's fishless cycle.

Question regarding my ORP Probe and readings......since I started it up its been like 130 - 165/175

Is this normal or kinda low? What should the range be at this point and going forward?

Looks like according to my Apex chart it's kinda climbing steadily though.

ca1ore · Jan 23, 2018

It can take weeks for a new ORP probe to 'settle'. Mostly a useless measurement anyhow.

cccharliecc · Jan 23, 2018

haha...yeah, I've kinda read that....but good to know, be in the correct range at some point.

mckinleyw · Jan 23, 2018

anywhere in between 300 and 400 I think is where you would want it. mine normally runs low 300s or right under 300. I have times where It will be all over the place though so I just use it for a reference

Reef Jeff · Jan 23, 2018

Yep...takes a good week or two depending on the probe. Sometimes they will stay stuck between 100-200 for a few days and then start climbing slowly until they finally settle in. Mine runs between 325 and 350 normally. I used to use it to control an ozone reactor, but I don't use that approach anymore. Newer techniques have provided high water quality so I no longer need ozone to keep a very nice system stable.

I disagree about it being a worthless measure. I use it as a quick reference just like I do with temperature and PH. You will notice a swing day to night which is normal. The actual number means less than the TREND. When it starts to trend down, it can be an indicator of reduction components accumulating like increased organics, skimmer off line, addition of livestock, or if significant, death of something.