The impossible question to answer

[am3gross]

Here it goes.

ORP, I have never put thought into this number that my apex reads, However, I understand that as it drops it may be due to some imbalance in the tank. With that said, My ORP has been dropping. My question is why?

Parameters have been very stable, IMO. All samples done with Trident or Hanna while confirming with Salifert.

PO4- .05-.1
NO3- 10-25
ALK- 7.85-8.1
CAL- 400-430
MAG-1385-1450

More on the situation,

Recently had to catch a Coral Beauty that was nipping at my SPS, I fed alot more over the 2 days of me trying to catch him. Maybe with the extra feedings and moving some rock around caused this? Maybe but the drop has been happening over the last month, So I feel there is more.

I did try some vinegar dosing, but that lasted 4 days, as it seemed to drop my PO4.

I added a new tang, about 2-3 weeks ago, could that cause it?

I have had no deaths in the tank, everything looks amazing ( polyps coming out of the nipped SPS even) and I see no Ill effects at all.

However, I still am curious about it. Any insight? Should I not even worry about it?


Thanks!

Mike

 

[killer2001]

http://reefkeeping.com/issues/2003-12/rhf/feature/index.htm

 

[Randy Holmes-Farley Verified Community Expert]

I do not think terms like imbalance should be applied to ORP since it implies something is wrong.

You have not mentioned what the ORP values seem to be or how much they changed.

 

[AKL1950]

My Apex has been running for about 3 1/2 months now. When I first got it started, OPR was around 280. It slowly rose to 400 over 3 weeks, then back to around 280 in about a week. It continued to do this cycle over the entire time. Bit of a head scratcher, but then I saw the relationship of the swing with my salt water storage tank and the rise and fall of OPR. Its a 75 gallon storage tank. It has a pump which constantly cycles the water. Also, it’s connected to my DT with a dosing line for my auto water change. When the tank is full, the OPR drops. There is no waterfall effect as the water cycles through the storage tank. As the tank empties, greater waterfall effect and OPR rises. Fill the storage tank again and OPR drops. OPR has a direct relationship to how much oxygenation is going on in the storage tank. Don’t know if that is true, but it’s pretty spot on. I dose 2 gallons a day and that uses 42 gallons over 3 weeks and then I refill the storage tank.

Jetson

 

[piranhaman00]

ORP means nothing, unplug it

 

[AKL1950]

ORP means nothing, unplug it

Interesting Statement. Care to share the science and facts to go with that statement?

 

[am3gross]

I do not think terms like imbalance should be applied to ORP since it implies something is wrong.

You have not mentioned what the ORP values seem to be or how much they changed.

My ORP was over 400, now my high is 338 with dips down to 296

 

[Rmckoy]

ORP means nothing, unplug it

This statement makes me question why Sometime would even exist if it means nothing .

 

[Bada Bing]

ORP means nothing, unplug it

For some perhaps but for others, understanding ORP can be a reasonable general measure of tank health/stability.
https://atlas-scientific.com/blog/h...tion potential, or ORP,of oxygen in the water.

 

[Randy Holmes-Farley Verified Community Expert]

For some perhaps but for others, understanding ORP can be a reasonable general measure of tank health/stability.
https://atlas-scientific.com/blog/how-to-lower-the-orp-in-a-reef-tank/#:~:text=Oxidation-reduction potential, or ORP,of oxygen in the water.

While ORP changes can be useful to detect unusual events, I don’t think the absolute ORP value is a general measure of tank health, and I’m not sure what sort of stability you are referring to.

 

[piranhaman00]

This statement makes me question why Sometime would even exist if it means nothing .

In our reef aquarium it means nothing, why exist? To sell to people who think it matters , cough apex cough

 

[Bada Bing]

While ORP changes can be useful to detect unusual events, I don’t think the absolute ORP value is a general measure of tank health, and I’m not sure what sort of stability you are referring to.

Well, as a practical measure in an aquarium, Redox potential is the ability of various beneficial bacteria (i.e. aerobic/anaerobic) to stay in balance. This is why a value of between 300 and 400mmV is recommended. In its simplest definition, Oxidation is adding oxygen to the molecule (waste) and Reduction is removal of oxygen from the molecule (waste). Aerobic and Anaerobic bacteria provide this level of waste breakdown. It also explains why ORP levels are typically low in a new aquarium, the Anaerobic bacteria have not had a chance to develop. If your ORP drops precipitously and doesn't recover, you got an issue. Alternately, if you consistently have ORP levels above 400, you may be over oxygenating.

 

[piranhaman00]

Well, as a practical measure in an aquarium, Redox potential is the ability of various beneficial bacteria (i.e. aerobic/anaerobic) to stay in balance. This is why a value of between 300 and 400mmV is recommended. In its simplest definition, Oxidation is adding oxygen to the molecule (waste) and Reduction is removal of oxygen from the molecule (waste). Aerobic and Anaerobic bacteria provide this level of waste breakdown. It also explains why ORP levels are typically low in a new aquarium, the Anaerobic bacteria have not had a chance to develop. If your ORP drops precipitously and doesn't recover, you got an issue. Alternately, if you consistently have ORP levels above 400, you may be over oxygenating.

…..

Yes because over oxygenation is a problem in our aquariums

 

[Randy Holmes-Farley Verified Community Expert]

Well, as a practical measure in an aquarium, Redox potential is the ability of various beneficial bacteria (i.e. aerobic/anaerobic) to stay in balance.

Why do you believe that? If its just from random reading of reef hobby blogs and such, I think it is unlikely to be true.

 

[AKL1950]

Why do you believe that? If its just from random reading of reef hobby blogs and such, I think it is unlikely to be true.

Randy, is it important or not? Is there a usefulness in monitoring ORP.

 

[ReefGeezer]

I view ORP as a measure of the capacity of the water to oxidize organics. I used it years ago as an indication of ozone levels. I also found that any number of things changed the ORP i.e. adding freshly mixed salt water, feeding foods that increased dissolved organics, changing out GAC, & etc.. I also found it changed by 100 or more for no discernable reason. For those reasons, I stopped using ORP as a measure of anything.

 

[Randy Holmes-Farley Verified Community Expert]

Randy, is it important or not? Is there a usefulness in monitoring ORP.

I eventually pulled my ORP probe out as I never responded to it.

from my article:

ORP and the Reef Aquarium - Reefkeeping.com

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.

 

[piranhaman00]

Randy, is it important or not? Is there a usefulness in monitoring ORP.

As I already mentioned, no it’s not, it’s a pointless measurement in reef aquarium.

 

[AKL1950]

As I already mentioned, no it’s not, it’s a pointless measurement in reef aquarium.

When I was 5 years old and my Dad said “Don’t do that” I couldn’t help but ask ”Why”. “Because I said so“ never seemed to satisfy me.

I eventually pulled my ORP probe out as I never responded to it.

from my article:

ORP and the Reef Aquarium - Reefkeeping.com

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.

Thanks Randy

Since it’s part of the Apex system, right now I see no reason to remove it. Just don’t obsess over it. From your article, I get that if I see something bazaar happen, like a quick 200 point rise or fall, sit back, think about it and investigate. Could be a measurement error, could be I changed something I shouldn’t have, or maybe I need to recount all my critters to see if someone is missing.

Jetson

 

[am3gross]

This is some good conversation. I also will not remove the ORP as I see no need, useful or not. I spend alot of time testing, checking the apex, paying attention to changes that happen, and like others, I wonder why. This conversation has answered some of those questions. Thank you all for the conversation!