Can someone "dumb" down ORP for me?

Cory · Dec 30, 2020

Montiman said:
Right now I have a Clearwater Tech but it is about 8 years old and the output is declining. I want to upgrade to an Ultralife.

Which version will you need? The mega? I was also thinking that uv generated ozone is more reliable. Why do you use ozone? For me was water clarity and destruction of organics. Are you using it in a skimmer? My old skimmer got cracks in it from ozone.

Montiman · Dec 30, 2020

Cory said:
Which version will you need? The mega? I was also thinking that uv generated ozone is more reliable. Why do you use ozone? For me was water clarity and destruction of organics. Are you using it in a skimmer? My old skimmer got cracks in it from ozone.

I started ozone because I was working at public aquariums and every tank had ozone. I decided I would try it at home so I did and the clarity has been amazing. It would be hard for me to go without ozone after seeing the difference.

I too think the UV ozone generators sound simpler and easier to repair if needed.

taricha · Dec 31, 2020

brandon429 said:
every interstice is open and exchanging and they were plugged up bigtime before the storm and complete water change

surely the trending ORP must be higher in the new setup??

I'm on the fence on this. I think you are correct and the ORP should be measurably higher, at least within one tank after it's settled post-cleaning.

But let me make the opposite argument. When I sample porewater from over 1" deep in the sand bed that I haven't attempted to vacuum in years, I find measurable O2: 10 or 20% of Max O2, but also the smell of H2S.
O2 and H2S production do not coexist, so this probably means that pockets of (relatively) higher and very low ORP are very close within < 1cm of each other within the sandbed.

So if the sandbed is so dramatically out of ORP-equilibrium with itself on a sub-cm scale - if the sand doesn't talk amongst itself from 1cm to the next, then do we really think the bulk tank water talks to the deep sandbed in terms of ORP?

But let's test it:
Pull tank water into two bottles, one with a generous slice of the sandbed in the bottom of the bottle, the other no sand. Slow bubble each with an airline (1 bubble every few sec) and then test ORP the next day.
If dirty sand drags ORP down, then the bottle with none should be much higher, having been totally separated from the sand.

brandon429 · Dec 31, 2020

Taricha that's very helpful to read thank you for the insight this forum rocks

We hadn't really asked for orp testing in the matter but now with piqued interest we can find a new party soon to test as you mentioned, looking forward

Courtney Aldrich · Dec 31, 2020

Montiman said:
I thought I'd chime in. I am an Ozone user. I would not have started measuring ORP except for starting ozone. I would not even look at ORP for 1-2 weeks and then start watching it. It is important to know what the ORP is in your unique system. I have had a couple times where my ORP alarm has notified me of an important problem.

Once ORP dropped below 20 and I found that my bio pellet reactor was clogged. After unclogging and cleaning the reactor the ORP returned to normal. Another time my copper band decided to start eating a football sized clam. The clam died even though the copper band didn't eat it at all and ORP dropped. After removing the dead clam and doing a water change ORP returned to normal. Another time I had a 1 foot clown tang swim into an urchin and die. Orp dropped, Apex alerted me and I removed the fish stopping the pollution.

The inaccurate oversimplification of ORP is that it is the balance of oxidizers to reducers in the water. On average oxidizers clean things, think Ozone, Hydrogen Peroxide, or OxyClean. Reducers are generally dirty primarily various organic compounds. If ORP suddenly drops it can be a sign something is dead or dying. If ORP suddenly spikes it can be a sign that some oxidizer is being overdosed.

Any chemist will tell you this is a complete oversimplification and it is, but it is useful and monitoring ORP can alert you to problems.

As a chemist, this is a beautiful explanation of ORP and how the value can be productively used.

Turd Ferguson · Jan 4, 2021

Is there a rule of thumb one can use when selecting the amount of Ozone to apply per gallon, per day? I'm back in the hobby after a 12 year break and recent dusted of my Red-Sea Ozone Generator (0-50mg/h) so it clean clear up the water, and perhaps assist with diatoms in the tank.

Back when I had my 75G I couldn't afford a OPG Analyzer and Probe as most were industrial grade (i.e. Honeywell), therefore I kinda ball parked it, running at 5-25% of full scale. It was connected to a H&S Skimmer with carbon on the lid and flow output.

Fast forward I connected it to my 40 IMO tank, ran it at 50%, smelled a little ozone so dialled it backed to about 25%. Water is clear, no ozone smell and I'll likely dial it down to 5% to be on the safe side. Sump included i'm at about 55G

That said, I've now a APEX but honestly, and as a process instrumentation guy, I'm not sold on a $75 ORP probe, it's accuracy and repeatability which is why I ask if there is a rule of thumb per gal/day. Rather not spend the $$ and I don't need to run ozone 24/7.

Thanks,
Turd.

Randy Holmes-Farley · Jan 4, 2021

John08007 said:
Without reading all of these posts, the higher the number the cleaner the tank. Watching BRS videos I never calibrated my apex orp probe, but I run my tank st 350

you should read first. Your statement is wrong.

John08007 · Jan 4, 2021

Randy Holmes-Farley said:
you should read first. Your statement is wrong.

What's wrong? In the brs video randy said with the cost of the calibration fluid it wasn't worth calibrating the probe but to instead use the number to see trends occurring by it rising or falling. I know with my apex showing my orp of 350 the water is to the point that I feel it's pretty clear, corals and fish appear happy.

I use it to control my ozone going into my skimmer. Im.sure I could get the orp higher but I'm happy with where it is.

Gabe · Jan 4, 2021

Softhammer said:
If you’ve made it 10 years successfully I recommend taking the probe and putting it back in the box.

those last four words... man I thought you were going somewhere else entirely!

Jeffcb · Jan 4, 2021

30 yrs ago I had an OPR meter and an Ozinizer, Don't use ozone in the house. Just don't

Randy Holmes-Farley · Jan 5, 2021

John08007 said:
What's wrong? In the brs video randy said with the cost of the calibration fluid it wasn't worth calibrating the probe but to instead use the number to see trends occurring by it rising or falling. I know with my apex showing my orp of 350 the water is to the point that I feel it's pretty clear, corals and fish appear happy.

I use it to control my ozone going into my skimmer. Im.sure I could get the orp higher but I'm happy with where it is.

Your literal statement " the higher the number the cleaner the tank" is wrong. That is most easily demonstrated by watching ORP after a water change. It usually drops. Not because the water is more dirty after the change, but simply because the trace elements in new salt water (such as iron) are more likely to be in a reduced (and more soluble) form that lowers orp. Ferrous iron (lower ORP), for example, as opposed to ferric iron (higher ORP)

ORP is certainly important to monitor when using a lot of ozone to be sure you are not overdoing it.

brandon429 · Jan 5, 2021

Will that initial drop go back up to be in relation to overall balance vs simply stay low until next water change, if the overall reef is in an oxidative vs acidic state?

brandon429 · Jan 5, 2021

Can orp be used to discern clean vs not clean tank status after a delay in measure after the water change?

Trying to find at least one/ any validation option for this measure that so many have attributed to changes in organic states in the tank.
The conflict is the crowd says its tied to tank changes they can alter by feeding more/ cleaning more and the measures strongly correlate to water clarity but the chemistry stated seems to imply its totally useless as a tank reference, zero cause and effect can be attributed

Randy Holmes-Farley · Jan 5, 2021

brandon429 said:
Can orp be used to discern clean vs not clean tank status after a delay in measure after the water change, accounting for those conditions mentioned regarding oxidation states

Trying to find at least one/ any validation option for this measure that so many have attributed to changes in organic states in the tank. The conflict is the crowd says its tied to tank changes they can alter by feeding more/ cleaning more and the chemistry is implying its totally useless as a tank reference, zero cause and effect can be attributed

A water change is just one of many things that reefers do that alter ORP without making the water cleaner or dirtier.

One issue is that the term "dirty" and clean" may have different meaning to different people.

Folks add trace elements all the time. Those will impact ORP. Most folks use more reduced forms because they are more soluble, and those may reduce ORP.

Some folks add vitamin C. That will drop ORP through the floor, as will anything called an "antioxidant" such as other vitamins (whether in foods or as pure additives).

Lugols for iodine will tend to raise ORP since I2 is a high ORP material.

Hydrogen peroxide is a complicated story, but it's addition appears to lower ORP.

ORP rises as pH falls.

In any case, that does not mean that ORP is useless. Watching it and looking for unusual rises or falls may alert one to unusual events in the tank, or may keep folks from overdosing oxidizers.

brandon429 · Jan 5, 2021

That's big picture helpful, appreciated

John08007 · Jan 5, 2021

Randy Holmes-Farley said:
Your literal statement " the higher the number the cleaner the tank" is wrong. That is most easily demonstrated by watching ORP after a water change. It usually drops. Not because the water is more dirty after the change, but simply because the trace elements in new salt water (such as iron) are more likely to be in a reduced (and more soluble) form that lowers orp. Ferrous iron (lower ORP), for example, as opposed to ferric iron (higher ORP)

ORP is certainly important to monitor when using a lot of ozone to be sure you are not overdoing it.

Suppose I should've used the term clearer, as opposed to cleaner. Does running ozone, having clearer water have any benefits other than being visually more appealing ? I would assume it would have a minor effect on light penetration.

Randy Holmes-Farley · Jan 5, 2021

John08007 said:
Suppose I should've used the term clearer, as opposed to cleaner. Does running ozone, having clearer water have any benefits other than being visually more appealing ? I would assume it would have a minor effect on light penetration.