Should I be worried about this drop in ORP?

[Dvir]

Hi all,
I have a 280g fish only tank, currently with 5 fish, I introduce fish very slowly. Tank was cycled for 3 months before introducing fish and I monitor ammonia/nitrite/nitrate. Fish are introduced at least 3 weeks apart.

I'm seeing a constant drop in ORP as the PH raises with the move to spring season and having more open windows. I'm not sure where ORP will stop, current minimum is at 138. I know recommended minimum is 200 but also read in a number of places that ORP need not be tracked at all. Is this something I should worry about?

Thanks!

 

[gbroadbridge]

Hi all,
I have a 280g fish only tank, currently with 5 fish, I introduce fish very slowly. Tank was cycled for 3 months before introducing fish and I monitor ammonia/nitrite/nitrate. Fish are introduced at least 3 weeks apart.

I'm seeing a constant drop in ORP as the PH raises with the move to spring season and having more open windows. I'm not sure where ORP will stop, current minimum is at 138. I know recommended minimum is 200 but also read in a number of places that ORP need not be tracked at all. Is this something I should worry about?

Thanks!

When did you install and when was the last time you cleaned and recalibrated the pH and ORP Probes?

They do need regular maintenance.

Regardsless, as long as you haven't spotted anything dead and are performing water changes it's unlikely to be of any concern.

 

[blaxsun]

I find that the ORP measurement is kind of a mixed bag of snakes. I know there's a correlation between pH and ORP, so I think the increase in pH probably explains some of the ORP drop.

My ORP has dropped from a 375 average to around a 325 average over the past few weeks, and nothing has changed except the weather. My probe is probably due for a cleaning as well.

I agree with @gbroadbridge.

 

[Dvir]

When did you install and when was the last time you cleaned and recalibrated the pH and ORP Probes?

They do need regular maintenance.

Regardsless, as long as you haven't spotted anything dead and are performing water changes it's unlikely to be of any concern.

5 months I calibrated only PH though.
What is the cleaning procedure? just wipe it gently with a cloth outside water?

Thanks

 

[gbroadbridge]

5 months I calibrated only PH though.
What is the cleaning procedure? just wipe it gently with a cloth outside water?

Thanks

I keep meaning to write a mini article on the care and feeding of various aquarium probes and gadgets - one day ...

If you have a ph probe cleaning solution you can use that for both.
The main issue is build up of proteins on the glass bulb.

Generally speaking you should refrain from wiping it as it can damage the bulb.

 

[metalle]

Yes, carefully clean the probe, but before you do. Measure a know “good” source of saline water from your LFS. Then gently remove any sediment. Follow the probe calibration process. Mine is 300 and dives to 260-280 after feeding. But recovers… I see some correlation with protein skimmer.

 

[homer1475]

First thing I did when I got my apex, threw the ORP probe in the trash. You can read the value, but little you can do to change it, and it's mostly a useless value. No idea why neptune decided to include that probe instead of a salinity probe(although they are flaky at best too) with most of their packages.

 

[Dvir]

If you have a ph probe cleaning solution you can use that for both.

I have calibration solution. Couldn't find a cleaning solution for the ph probe (google). Is there one made by apex or 3rd party?

 

[taricha]

Moves in ORP would only be helpful to know if you were using ozone or similar, then ORP measure would mostly track how that oxidizer is doing in your system.
Otherwise it reacts to random reducing and oxidizing compounds that you don't really care about (like fish food).

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, it is normal and expected for ORP to drop as pH rises. The article below has a very involved theoretical discussion of the reason, and the real result in a typical aquarium.

ORP and the Reef Aquarium - Reefkeeping.com

 

[Dvir]

Moves in ORP would only be helpful to know if you were using ozone or similar, then ORP measure would mostly track how that oxidizer is doing in your system.
Otherwise it reacts to random reducing and oxidizing compounds that you don't really care about (like fish food).

So is there no "minimum" value I should worry about?

 

[Randy Holmes-Farley Verified Community Expert]

So is there no "minimum" value I should worry about?

Not really. Very low values are more likely test error.

 

[RedoubtReef]

Is there even a reason to measure ORP in a fish only tank?

 

[Randy Holmes-Farley Verified Community Expert]

I removed my ORP probe since I found it not useful, but this is my general comment on it from the article linked above:

Recommendations for ORP

ORP is an interesting, if complicated, measure of the properties of water in a marine aquarium. It has uses in monitoring certain events in aquaria that impact ORP but may be otherwise hard to detect. These events could include immediate deaths of organisms, as well as long term increases in the levels of organic materials. Aquarists that are monitoring ORP in an aquarium, and are doing things that otherwise seem appropriate for maintaining an aquarium (such as increasing aeration, skimming, use of carbon, etc.) may find monitoring ORP to be a useful way to see progress.

ORP measurements are very susceptible to errors. Aquarists are strongly cautioned to not overemphasize absolute ORP readings, especially if they have not recently calibrated their ORP probe. Rather, the most useful ways of using ORP involve looking at changes in measured ORP.

Some aquarists use oxidizers to raise ORP. Those additions may be of benefit in some aquaria, and they may be beneficial in ways that aren't demonstrated by changes in ORP alone. I've never added such materials to my aquarium. In the absence of convincing data otherwise, such additions seem to me to have more potential risk than is justified by the demonstrated and hypothesized benefits.

 

[RedoubtReef]

I removed my ORP probe since I found it not useful, but this is my general comment on it from the article linked above:

Recommendations for ORP

ORP is an interesting, if complicated, measure of the properties of water in a marine aquarium. It has uses in monitoring certain events in aquaria that impact ORP but may be otherwise hard to detect. These events could include immediate deaths of organisms, as well as long term increases in the levels of organic materials. Aquarists that are monitoring ORP in an aquarium, and are doing things that otherwise seem appropriate for maintaining an aquarium (such as increasing aeration, skimming, use of carbon, etc.) may find monitoring ORP to be a useful way to see progress.

ORP measurements are very susceptible to errors. Aquarists are strongly cautioned to not overemphasize absolute ORP readings, especially if they have not recently calibrated their ORP probe. Rather, the most useful ways of using ORP involve looking at changes in measured ORP.

Some aquarists use oxidizers to raise ORP. Those additions may be of benefit in some aquaria, and they may be beneficial in ways that aren't demonstrated by changes in ORP alone. I've never added such materials to my aquarium. In the absence of convincing data otherwise, such additions seem to me to have more potential risk than is justified by the demonstrated and hypothesized benefits.

yep, I read that about a week or so ago when trying to decide if I needed to use mine at some point. I decided not to based on this.