What if your ORP is going down?

[NEFFx]

So ORP, always an interesting topic. That said there appears to be some correlation to bacteria levels and ORP, and clean water.

So that’s my concern of the unknown. My ORP is on a downward trend, what does one do. Is Cyano imminent? Diatoms? Is everything ok? What are your thoughts?

 

[rhostam]

Here is an article by one of our resident experts:

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

 

[((FORDTECH))]

Here is an article by one of our resident experts:

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

Do you have any idea how many times I’ve read this complicated article and still have no clue. every time I see a thread someone posts about orp I get excited because I think I might get some resolution for my orp questions and issues. And every time in the thread someone posts this article lol. Anyways my orp is 206 along with system not doing so well and I wish I knew if 206 means anything g or do I continue to ignore it. Last few weeks I’ve been thinking I have a bacteria issue and now I see op say in his post he knows there is a connection between bacteria and orp and how clean water is. Well I will follow this but not hold my breath

 

[rhostam]

Do you have any idea how many times I’ve read this complicated article and still have no clue. every time I see a thread someone posts about orp I get excited because I think I might get some resolution for my orp questions and issues. And every time in the thread someone posts this article lol. Anyways my orp is 206 along with system not doing so well and I wish I knew if 206 means anything g or do I continue to ignore it. Last few weeks I’ve been thinking I have a bacteria issue and now I see op say in his post he knows there is a connection between bacteria and orp and how clean water is. Well I will follow this but not hold my breath

When I have (bacterial/ algae) blooms my ORP always drops from “baseline” and I take it as a sign something is wrong, or at least something I should investigate.

 

[Sean Clark]

Orp is very complicated. My normal orp is around 350. If I do a water change it will plumit to around 250. This has nothing to do with bacteria in my system.

 

[((FORDTECH))]

Orp is very complicated. My normal orp is around 350. If I do a water change it will plumit to around 250. This has nothing to do with bacteria in my system.

I’m normally 250-280 but did water change 5 days ago and it dropped to 205 and has been there since. Maybe bubble stuck in probe.

 

[Sean Clark]

I’m normally 250-280 but did water change 5 days ago and it dropped to 205 and has been there since. Maybe bubble stuck in probe.

Possibly, is your probe somewhere that would allow bubbles? Also does the timing correlate?

 

[((FORDTECH))]

Possibly, is your probe somewhere that would allow bubbles? Also does the timing correlate?

Well when I did water change drained sump close to bottom then pump water back in to fill back up. When doing this all probes are out of water for 10-20 seconds and water being pumped back in causes air bubbles so guess it’s possible

 

[((FORDTECH))]

I originally was thinking did the water i used for water change contain so much bacteria it lowered orp so much

 

[Sean Clark]

Well when I did water change drained sump close to bottom then pump water back in to fill back up. When doing this all probes are out of water for 10-20 seconds and water being pumped back in causes air bubbles

ORP generally needs a few days to "settle" as well. So if they were out of water I would allow a few days before I trusted any ORP ouput. A lower ORP after a water change is very normal. I would not be concerned about it. I would presume that it will rise back up over time.

 

[((FORDTECH))]

ORP generally needs a few days to "settle" as well. So if they were out of water I would allow a few days before I trusted any ORP ouput. A lower ORP after a water change is very normal. I would not be concerned about it. I would presume that it will rise back up over time.

I hope so but I still feel my normal is to low when I read how most average 350-430

 

[Sean Clark]

I hope so but I still feel my normal is to low when I read how most average 350-430

I am no expert but I think this depends on organics in vs organics out but this is countered by organic free saltwater. For me fresh mixed saltwater has a low ORP and should have zero organics. One would think that this should have a higher ORP but it does not. Super confusing.

 

[NEFFx]

this may be misinterpretation of the article posted earlier and also the one by Randy who also thinks it’s confusing so I’m ok with having little understanding.

i think ORP is the balance of good bacteria and the stuff it eats. When I add amino acids, AB+, food, it shoots down. When I have good bacteria levels it comes back up ok. I also use live rock enhance (bacteria booster? It was explained to me) and reef enhance to help bolster the bacteria levels since I don’t have tons of rock.

i had a cyano bloom back 4 months ago and ORP was sitting in the 200s then. I don’t want to deal with chemiclean etc. So wanted to know what others thoughts were, though I have seen a correlation to good bacteria levels and ORP. I’ve always had very low nitrates and phosphates though these stages and I dose nitrate now.

 

[Randy Holmes-Farley]

So ORP, always an interesting topic. That said there appears to be some correlation to bacteria levels and ORP, and clean water.

IMO, the clean water idea related to ORP is mostly myth, but higher bacteria levels may spur lower ORP.

 

[Randy Holmes-Farley]

Do you have any idea how many times I’ve read this complicated article and still have no clue. every time I see a thread someone posts about orp I get excited because I think I might get some resolution for my orp questions and issues. And every time in the thread someone posts this article lol. Anyways my orp is 206 along with system not doing so well and I wish I knew if 206 means anything g or do I continue to ignore it. Last few weeks I’ve been thinking I have a bacteria issue and now I see op say in his post he knows there is a connection between bacteria and orp and how clean water is. Well I will follow this but not hold my breath

I'm more than happy to explain anything that I can about ORP or things in the article, but neither explanations nor more understanding will lead to any great insight as to how to use ORP in aquarium husbandry.

It is inherently complicated with many different controlling factors in a reef tank, and many simplistic claims about it are, IMO, wrong. The higher ORP means cleaner water things is clearly wrong. There's no clearer proof of this than that mentioned above: ORP in a salt mix that is free of any organics being lower than a reef tank simply because of the choice of form of trace elements added.

Here's an analogy that might help clarify what I mean.

What if there was a value that ICP provided that was 6 trace metals added together. Iron, manganese, vanadium, zinc, chromium and tin. Your tank has 100 ug/L. Good? Bad?

A super high value and a super low value are obviously suboptimal. Things in between? Hard to say.

 

[Randy Holmes-Farley]

i think ORP is the balance of good bacteria and the stuff it eats. When I add amino acids, AB+, food, it shoots down. When I have good bacteria levels it comes back up ok. I also use live rock enhance (bacteria booster? It was explained to me) and reef enhance to help bolster the bacteria levels since I don’t have tons of rock.

Try measuring the ORP in the amino acid solutions. It may be very low, possibly from preservatives in it (bisulfite, metabisulfite, vitamin C) or from the use of reducing amino acids, such as cysteine.

 

[Randy Holmes-Farley]

I’m normally 250-280 but did water change 5 days ago and it dropped to 205 and has been there since. Maybe bubble stuck in probe.

Maybe.

Salt mixes are also often lower ORP due to use of low ORP chemicals such as ferrous iron which are much more soluble than highly oxidized forms (e.g., ferric iron).

 

[NEFFx]

@Randy, I wonder how many times you think to yourself why Neptune put the ORP probe on the standard Apex. And that they should remove it. Lol. The only time I ever read them being used over the past 20 years was with ozone generators and few people use those these days especially with the ultra clean tanks.

 

[blaxsun]

I don't claim to completely understand how ORP works, but there is a correlation with pH - and you can definitely notice when you add certain things like NOPOX, etc. My ORP ranges from a low of 390 to a high of around 430 throughout the day.

 

[((FORDTECH))]

I don't claim to completely understand how ORP works, but there is a correlation with pH - and you can definitely notice when you add certain things like NOPOX, etc. My ORP ranges from a low of 390 to a high of around 430 throughout the day.

Something in my head tells me that if I was seeing these numbers my tank would be doing better whether or not it’s the chicken or the egg theory I don’t know but something in my head is telling me this if I did whatever I needed to raise or P things would look better that’s why I’m trying to figure out what it is