Orp

[DonW]

Assuming that a low ORP reading is a indication that water quality is poor (excess disolved organics). Will a UV sterilizer raise orp?? If not is ozone the only way to rasise orp to the 350 mark??

Thanks
Don

 

[jase0723]

When I first got my ORP meter it read 295. I wanted to raise my ORP with out ozone, so all I did was water changes and got rid of all my sand execpt for a little bit in the front for looks only.

Combination of 25% water change on a weekly basis for one month and removing my sand and going bare-bottom raised my ORP to 475 and this is where it's been for the past 2 months. This process also got rid of my nagging trace amounts of nitrate.

 

[NaH2O]

Here is a link to an article by Randy Holmes-Farley: ORP and the Reef Aquarium

Have you noticed if your ORP changes after you clean your skimmer, feed, or do other things to your system? ORP can be a confusing topic, but I have read that there are some things that will change your ORP without the addition of ozone. I often wonder how important of a test ORP is. What do you think?

 

[Curtswearing]

Original post edited by Curtswearing

Things that lower ORP: Dysfunctional Skimmer, dirty filter pads, detritus buildup, increased biological reactions.

Things that raise ORP: Good skimming, not overstocking your tank, a few chemicals, keeping detritus out of the system.

 

[DonW]

I would be happy to see 350 to 375. I would also question your orp prob. 475 orp reading is pushing well into dangerous level.

Don

 

[NaH2O]

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.

The above quote is taken for the article I linked in my prior post. It seems it is important to watch the trends in your tank.

 

[DonW]

Ive always used orp as a water change indicator and a skimmer checker. I started this with my FO system years ago. If I try to keep it as close to 300 as possible without cleaning day and night all is great. Green algae production seems to fall off at about 300 orp. You get down around 200 it really gets going. You do need to calibrate the probe monthly to get accurate results. Anything over 450 I see negative results in my fish, I believe this also causes lateral line disease. I have a ozone generator but have not used it on my new system, I need to set up a different carbon system first or just bag it and go uv.

Don

 

[FishyinKy]

Sounds like you understand Orp then Don. Do you think powerheads and more circulation make a difference?

Mac

 

[DonW]

I think no matter what you do to increase water quality and circulation it will raise orp to a point. So far I have not been able to get above the 300 mark with my new tank. I never could get above 275 without ozone on my old system.
I do think that watching trends makes orp more useful. I would just like to get the trends into a higher range say 300 to 375.

Don

 

[NaH2O]

Let me clarify a few things. ORP = oxidation reduction potential. If you think of the ORP as a battle, you don't want either the oxidizers or the reducers to win. If either wins....that means your tank will be dead. The range of ORP 250-500 is important to note because if you are measuring ORP - you will want your value ~375. Also remember, a value of 250 is just as bad as a value of 500....again, you don't want either to win......you want a balance. The higher the ORP value, the greater oxidation ---> greater reduction potential. There are some members of each team that could be considered the star....for example: ozone is a big oxidizer. Hydrogen peroxide (H2O2) is also an oxidizer, sometimes referred to as "poor man's ozone". An oxidizing agent (electron acceptor) is a reactant that accepts electrons from another reactant. By contrast, the reducing agent (electron donor) is a reactant that donates electrons to another substance to reduce the oxidation state of one of its atoms. We can look at bacteria as one form of a reducer. So let's say you stick your ORP probe into a DSB....your ORP will drop, and continue the deeper you go. Using jase0723 as an example, when the sand bed was removed, the ORP (potential for reduction) increased quite a bit....makes sense because a large number of reducers were removed from the system. Same thing with a skimmer. Your skimmer gets covered in algae and other organic material, there will be reducers present, so....clean off your skimmer, you are removing the reducers present. Do you need ORP to know when it is time to clean your skimmer? IMO, no - you probably could just look at it and see when it is time. Can you use ORP as an indicator of water quality? I guess if you have a lot of decaying matter in your tank, you will have a larger number of reducers present - lowering the reduction potential. One last point - oxidizers and oxygenation are two different things.

 

[DonW]

Nikki,

It sound as if you bielieve that ORP is a useless measurement? Do you use a orp meter? Actually if you find the base line for your system you'll see just how useful it can be. Just to clarify I dont think its imposibble to see a jump to 475, but to see no reductin from 475 over a period of time is usually not the case. In fact its just plain unnatural. All tanks have reductor in one form or another.

Don

 

[SaltyDog]

O.R.P. = Over Rated Purity

My 180 reef is at 350 and my 400FO is at 400 for those who want to know. SD

 

[FishyinKy]

I have to say that the reason I started doing research on this was that I figured anything that helped keeping my tank more stable. . . Don't you think this will do it?

Mac

 

[DonW]

It does help to know what your ORP is. Ozone will keep it very stable. Depending on your system I dont know if you would benefit from ozone. I would start by getting an ORP controller and keeping track over a periond of time before investing in ozone. We have all heard stories about corals and fish starting to die off overnight, I believe this helps minimize severe problems by giving you a heads up before all goes bad. I do not run ozone yet, just because I have not had the time to get the skimmer prep done (carbon filters). I can tell you that I had a sponge about 4" diameter just start to die off and my orp dropped by 10 daily until I removed the sponge, the next day it started going back up. If you decide to use ozone do alot of research on carbon filters (lid for the skimmer and out flow) and use two controllers as a failsafe.

Don

 

[Ray Pollett]

Personally I quite doing ORP readings on my tanks. I find it useless in most cases. I personally find the animals in the tank are a much better indicator of water quality than ORP is.

Ray

 

[FishyinKy]

It strikes me as very interesting that you had to go to a barebottom tank to get your levels to a satisfactory place for you and also that it eliminated your nitrates. As I understand it nitrates are a part of the orp?

mac

 

[mojoreef]

ORP is kind of a tough one. It can remotely relate to Water Quality but its really an interpatation. In our tank we have large populations of reducers (bacteria) and oxidizers. Either one cannot live where the others are due to enviroments. So if you have to many reducers your tank will die, if you have to many oxidizers your tank will die. So a ORP monitor lets you know that the balance between the two is fairly even. As this relates to Ozone is that Ozone is a very active oxidizer, so it will tip the scale in this battle towards them and your orp level will go up. You have to use a monitor for Ozone use as once again if the oxidizers get to high your tank dies (or basically everything in it get oxidized). Thats really the reason orp monitors came into play was to watch ozone input.
Anyway you could loosely relate it to water quality, but usually you will have a lot of other signs in the tank to let you know things are not going well.


kind of a loose explaination but thier ya go.



Mike

 

[NaH2O]

It sound as if you bielieve that ORP is a useless measurement? Do you use a orp meter?

I believe that ORP is a very beneficial measurement if you are using ozone. I do not use an ORP monitor, as I don't use ozone and also, I agree with Mike when he said the following:

Anyway you could loosely relate it to water quality, but usually you will have a lot of other signs in the tank to let you know things are not going well.

 

[jks1]

I just started using an ORP monitor. I read as much as I could and think it can be benificial as a quick glance at "water quality". I look at it as a trend analysis device. Most of my reading said the actual level is not as important as consistancy from day to day.

As some mentioned- a drop of ~50 might lead me to investigate a dirty skimmer, or ensure all pumps are functioning. I caveat this in that I do believe the appearance of animals is invaluable in determining the state of things in our tanks.

I had the monitor up since day one on the new tank and it was interesting to watch the readings as the tank cycled. I started with fresh LR- ~200lbs. Initial readings after adding the rock were in the 100ppm range as the reducers were working overtime. As the cycle progressed the readings continue to climb. I just completed the nitrite portion of the cycle and Im seeing readings in the 275 range. I assume it will continue to rise in the future.

One thing I dont really understand is in the last week or so I have seen quite a bit of hair algae and green film algae on the glass. With the addition of the algae I would have expected the ORP to rise as I thought there would be more O2 in the water as a result of the algae, but I have seen no noticeable spike, just a steady increase of 10-20 ppm/day.

Also could someone explain why algae would appear at a lower ORP rather than a high one? I guess it has to do with reduction producing nitrates?

 

[DonW]

Thinks about what causes hair algae.
If thrives when reductors are plentiful (low orp).

Don