orp & contributing factors

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Dandj
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Post by Dandj »

Also the probes do not last for ever....
We have just replaced ours as it no longer showed the expected high when cleaning with H2O2, also bought some calibration fluid - the plan being to check how far aout the old probe was. Interestingly it still showed 400 in the calibration fluid but still failed to show the expected high in H2O2 so put the new probe on.....pond now 270 where it was reading 320 with the old probe..... :cry:
The pin point meters are not very accurate and should be used for observing trends -do not take the readings as gospel. This is a problem when dosing with PP for instance but still better than not monitoring.
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Post by Duncan »

hi all

you will have to forgive me if this makes no sense as i have just done my first night at work, up for over 24 hours and just up and not quite with it yet
if we are not careful we are in danger of getting this subject to the point nobody can understand but,

as usual Chi is right on the money and with all due respect some are slightly missing the point with redox which is what i prefer to call it

it is simply the reaction of one atom donating an electron and another accepting it nothing more nothing less this is thew bare nuts and bolts of the process one atom donating is not enough if its not accept by something the process is not complete

if we look at the addition of KMnO4 to a pond the redox reading will rise quite a bit as PP is a powerfully oxidizer if we look at the chemical formula we can see where the reaction is derived from

it not the potassium( K) its not the manganese (Mn) it these 4 buggers on the end the (O4) the "ate"
geez i must be tired i lost my thread,, oh yes

some we can establish that adding PP will raise ORP and make the water beneficial for nuking parasites and bacteria, now what if we could do the same without the addition of PP?

yes we can but lets take this a stage further before we get to this and add Ozone.

if we inject ozone gas to the water column we get a rise in ORP the reason is simple we have three oxygen atoms if you understand atomic structures the reason Ozone is so reactive is simply two company threes a crowd, we have three oxygen atoms joined together but two of them will be happy but three is not comfortable for the molecule the third atom does not want to belongs so its bouncing around all over the place trying to make its self have a purpose at the first opportunity the third will spring off and join up with the first thing that looks like a suitable mate and that is usually something organic at this point it will oxidize that matter so the oxygen has been reduced and the organic has been oxidized REDuced OXidized

it is more than possible to get the water REDOX reading up to the same state as if you were adding KMnO4 with the addition of anything other than Oxygen and keeping the system ultra clean and the organic load very Low. a typical PP reading for our 1.5 PPM dose is usually around 450 Mv if we could get the ORP reading to that figure without adding a chemical we would get the exact same beneficial results Parasites being nuked and bacteria being nuked as we did with the KMnO4 and we could achieve natural wound healing ETC:

as Chi quite rightly states this is very hard to achieve because of pond dynamics at work in a closed system
we have filters all fired up and producing organics which is using our our oxygen extra and therefor our redox potential we have usually and over stocked pond of fish that is also producing co2 and consuming O2 in a abundance also using our redox potential, pond temperatures also play a huge part in this reduction

to ramp the orp UP we need everything going our way to achieve a high potential its not impossible but it is very hard to achieve

now we get to the crux of the matter calibration and what if you cannot achieve these types of figures

calibration is paramount, the minute you place the probe in water its starting to go of its calibration as the probe electrode is being oxidized
calibration also has to be precise usually the reference on the side of a calibration fluid is a set Mv at a set temperature mine is 230 MV at 25 c if you dont achieve these two set criteria you may as well not have bothered you could be miles away and dont use an ORP checker fluid these are crazy and a joke as the operating range is so vast
so as with a tds meter Calibration is everything other wise the meter could be telling you anything but the truth but not only that could a million miles away and of no use

you must clean the probe periodically as it goes off, the good things is it usually comes up in measure in experience

ok you cannot achieve high values whats going on?

nothing you are simply normal like the rest of us your fish wont die any faster than normal its mearly showing you that your water has a certain level of pollution by virtue of the fact you cannot get to Nirvana
its showing you that you may be over stocked, you maybe dont have enough O2 going in or it cannot achieve saturation, you may have very high TDS readings, you may just simply be over feeding as chi points out

the point is at the end of the day its a guide and is pointing out; you could do better with out it costing you a fortune to achieve it. but unless the reading is very low and in the slammer your fish aint going to die

so treat it as a guide and to get too caught up in the Technicalities

for my money i have yet to see two calibrated orp meters that read the same anyway, and i have a few. so the only times i use mine is when i do a PP treatment, i get the ORP to 450 Mv and hold it there for 4 hours then reverse it and watch the orp come back down safe in the knowledge my fish are now safe
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Post by Gazza »

Well thats it in a nutshell then Dunc :lol: as always a fair response :wink:

I also agree with the meters and calibration as you well know Dunc calibration is more important than testing otherwise how do we know whats what!! and i do like a bit of calibration :lol: :lol: :lol:

I have a few ORP meters and i would think they are due for a bit of calibration so i will have to do them and then see what the difference is because as you say they never all read the same.

Whilst on the topic this is also the same for most other meters as when they are manufactured they will have to work within a certain tolerance so even when you have calibrated two meters (lets say two PH units) and got them to the same when testing some water one may say 7.8 and one could say 8.1 but both would be within the manufacturers tolerances :? :shock:
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Post by chita »

One could say a certain amount of tolerance is required to absorb and utilise all of this information!

As Duncan has tried to point out though, we are not dealing with absolutes here, but with approximations. The science requirement is basic, go beyond that and we would have to start discussing equipment at several hundreds or even thousands of pounds per meter to provide the discretion required. This makes any discussion on the atomic level superfluous and potentially confusing. Our koi do not have requirements measured to finite atomic scales, so for clarity discussion can and should be confined to the practicalities. I agree advanced debate on particle sciences can be interesting, it can also serve to deter the uninitiated from purchasing useful equipment.

The equipment designed for the hobby is more than tolerable, providing as it does reasonable interpretations of the facts. Used as intended it can provide more than adequate information to the hobbyist. There is so much to be gained from learning to understand such equipment, but best overall results are achieved if that learning is concise and focused on the task to hand.

There is much more I could say on the subject of ORP, however I have never felt the need to elaborate, for all the reasons above. I have offered a perspective on the use and applications of the devices, along with some of their idiosyncrasies, follow those simple guidelines and the koi will benefit without a doubt.

Chi
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Post by Fish4Friends »

Hi Duncan/All

First an apology, I believe my original post in trying to be brief was misleading as indicated in the first response from Gazza, also reading your last reply (Duncan) I think you felt I was querying your outline of the redox process, this is totally not true, I believe your layout and explanation is superb!

So thank you! For the response especially as you indicated you had just endured a long day! I appreciate your comment in trying to keep things simple and "effectively" not get caught in the technicalities, however as the cost of electronic measuring devices are falling, more keepers are changing from standard "chemical based" tests to the electronic equivalent is going to cause further confusion without a basic understanding of how/why the units work.

A number of observations have been made as to calibration, tolerance, temperature, electrode degeneration etc

As with one of Duncan’s original examples of a torch using the redox process to provide light, 2 identical torches, will differ and without sophisticated equipment the differences will not be apparent unless one is visually giving less light than the other!

To try keep things in perspective, the point I am trying to make is that with sophisticated instrumentation, unless an understanding of how/why a reading is given then that reading will have less value than one that is understood this includes even why simple “waterâ€Â
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Post by Duncan »

for those who may be interested i am currently writing an article to be published somewhere yet to be determined, purely on water science/chemistry right down to atomic levels the states of chage of the compnents there in and why the molecules do what they do why certain combinations are formed acids and bases

it may switch a lot of people off,, it is heavy reading, but if you have the determiantion to understand the true techy stuff like neutrons.electrons and protons it should clear a lot of things up about "water clusters", pH, GH and KH

so if you like tech, stay tuned
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chita
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Post by chita »

No need for apologies Graham, your observations were valid, just needed to try and get the message accross that it is actually possible to get good benefit from devices regardless of whether or not you understand the deeper science involved. I more than most am aware that one's enthusiasm, or even passion, can quickly lead to confusion for the uninitiated.

The best way I find to deal with the technical aspects of teaching is to write in "parallel prose". That is to provide the simple synopsis first before progressing to the more advanced background discussion. This way both factions benefit from being able to keep up, taking only what they need from any debate.

Many of us have little or no idea how some of the medications we use work, but the job still gets done.

All of that said, I would readily agree that the potential for improving derived benefits does indeed increase pro rata with understanding. And as Graham as also highlighted, equipment is getting cheaper.

With regard to user guides of any type Graham, I find that regardless how many such missives are produced, the majority find it easier to shout for help!

A repository of guides and usage methodology for the appliccable instruments might not be a bad idea. Again synopsis followed by tech info, providing a quick reference, from which one can then readily extract only the level of info required at the time.

Chi
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Post by Duncan »

hi Graham no problem mate i never thought that, i was tired though< grin>

just to be brief cuz im just out the door to the night shift

the type of meters used for typical orp readings in ponds are primative at best, i once spoke to thermo russel about there meters and in the cousre of the conversation it became apparent from them that unless you spend 1000's of £'s on one meter or another your gonna get at best a ball park figure and believe me they do run into thousands of £'s sorry but the 70 odd quid for a pinpoint just wont hack it if its accuracy your after but if you want a guide by all means it give you an indicator
and thats primarily why they take time to settle they just ain't that good at what they do for that price

look up thermo russels site and see what i mean

its a bit like video capture cards for computers for capturing camcorder movies , you can buy a perfectly normal and good one for around £30 and you will be pleased with it! its not till you see what a £2000 jobby can do as used by the BBC you realise you never bought a capture card at all

so thats what it comes down to in the end how deperate are you to know and if you need to know whats the point if its acuracy is questionable?

for your information i use a Ph meter electronic for all other readings is still use tetra kits, what these dont tell me i dont really want to know

cheers

dunc off to work now
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Post by chita »

Now I'll take a couple of queries I missed earlier in this thread, sorry guys!

Graham at one point posed questions relating to making allowances for dielectric factors (constant or otherwise) and insulators etc. I can answer this aspect very clinically, as it happens my elder son whilst at university set up a consultancy, one of the functions of which was writing firmware (chip based software) programmes for a variety of applications. Much of this output was for deployment within the instrumentation and control markets. Instruments simply take basic measurements, those taken by an ORP meter differ little or nothing from those taken by a TDS meter. The difference lies in the probe type and the chip based algorythms and firmware, for it is these which determine the output data, not the probes themselves.

So, the water aspects raised here are most certainly factored in, albeit there will always be some compromise where averages are concerned, discrepencies are minimal.

John, (Co2) you queried my response to Mark Gardners reported 400 ORP reading, firstly I would reiterate my comment at the time, that Mark I'm sure had his tongue at least a little way in his cheek.

I have conducted so many experiments with water related ORP/REDOX readings I'm unable to recount or even recall them all, but very very many over a few years. If I have a bee in my bonnet I spare no resources or expense, I demand answers in a timely fashion, answers in 2006 to questions raised in 2005 do me little good.

As a result of those tests I would state categorically that it is virtually impossible to achieve a reading of 400 unaided in a stocked koi pond which utilises a circulatory filtration system, even in a flow through pond you'd struggle.

As a practical demonstration of the facts please consider the following example.

I have a 3 pod water softener / pretreatment system, consisting of 1 x 5u sediment, 1 x 5u GAC and 1 x 5u carbon block of the highest possible quality. The output is then fed to a 3 membrane RO system, producing water between 1 and 5 TDS, GH and KH are so low as to be immeasurable, PH around 5.8 to 6.0.

The ORP/REDOX of this water measured at the outlet from the RO system is 400 to 420, need I say more? Realising this reading in a pond takes an incredible effort, maintaining such a reading an even more incredible effort!

My pond has 4 seperate filtration systems, turning over the pond approximately every 15 minutes, and that's only the basics. I have tried for nearly a year to improve on my 370 reading to no avail. There is not a speck of dust on the pond floor, the pond itself is self cleaning, defeating any settlement potential, still 370 max. The only way to achieve 400 is to supplement nature, whether chemically through PP or ozone etc, or biologically, but supplement it one must to achieve 400 ongoing.

Which brings us full circle, you will now understand my interest in Mark's experiments, for though I am aware of the two products and the reactions resulting from their combination, I place significant value on personal experience. I would therefore have liked the unhyped version from someone like Mark, unfortunately it was not forthcoming, so this summer I shall conduct the same tests for myself.

Chi
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Post by Fish4Friends »

Hi Chita

Please believe me when I say I understand the introduction of new information, I am a retired Lecturer, therefore have been used to transmitting new information, I also agree a synopsis will often give "base information" without the "deep exploratory" information needed for full understanding, however my main hesitation in this instant was the need to introduce a "totally" different area of knowledge!

This is based in electrical/electronic engineering and I would not inflict this on anyone that does not know why this is essential to needing to understand how the "electronic" meters work and how "previous" variables that did not influence (well not recordable) chemical test kits can make a difference to electronic measurements!

As a simple example "All electronic meters" work around "Ohm's Law" this is immutable! However how this is implemented is the basis for the individual meters!

The fact that water is a dielectric (with consequences) is also pertinent to "meter usage" where it had no impact on "chemical reagents" How?
Take a material that is an insulator, add an increasing potential across 2 electrodes until the K value is reached [MV/m] for pure water this is around 80, then the material changes from an insulator to a conductor so reducing the voltage necessary to maintain a constant current flow!

Now with absolutely no intention to belittle anyone, does that make sense? I have put the essentials as briefly as possible, but this "flip" within the properties of water as a "dielectric" makes a "Massive" difference to how meter measurement "stability" is influenced, this also ignores large numbers of other factors that change the readings (on all classes of meter!)

Chita as you (I believe) originally said for the ORP meter, it is the "equivalent" of having a "life meter" that without knowing what/how it is monitoring there can be no "accurate interpretationâ€Â
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Post by chita »

No problems at all Graham, I too have a little experience in the field, and as I also said in my previous post, virtually all such meters work on the same principle, though once again I chose not to elaborate. That choice was made consciously, as I do not believe adding more to the mix in this instant to be of benefit to the masses. Whilst OHMS law in and of itself is a simple equasion, the understanding required to extrapolate it's various resultant outputs per input is not always so. And again as stated previously, such excursions are unecessary for calculation purposes as this is all taken care of by design and or onboard firmware. The boffins have without doubt made allowances for numerous such factors during the design of the equipment, they being well aware of numerous related aspects of water composition. I would expect the manufacturers of Barbie doll's to get that simple bit right, it being hardly serious science.

My posts were based totally on meter derived measurements, which do indeed react differently than do chemical tets kits. But as stated above and in my previous post, we do not need to worry about about such matters, they are provided for in the design.

I also understand that the requirements of our koi, whilst more complex than many assume, are not so complex as to require that higher level of knowledge. Though I concede if the knowledge is freely proferred it would be prudent to assimilate same whilst it's on offer!

Which is where we begin to go around in another circle, it's about degrees of accuracy yes, but relative to the project in hand. Being able to ascertain the finite numbers and processes involved in such reactions, or how they are derived, as apertaining to this hobby, is of little consequence to the majority. Nor is it of any consequence to the fish, even were our understanding and readings 25% more accurate than now it would not improve our fishkeeping results, though the knowledge has a value beyond that of course.

The reason I say that are, we are talking about a target or goal here, so the way I perceive it is simple, though my analogy may be flawed as I'm not a "real" football fan!

If a goal mouth as a "target" is 20' wide, it matters not a jot if I place the ball 1" inside the post or in the centre of the goal mouth, if it goes past the keeper it's a 100% goal.

Similar conventions apply to this aspect of Koi keeping, we have a certain "target" area, being good enough to get it in the centre of the goal mouth does nothing to improve the results, "just" clearing the posts on the inside would be just as good. Still a 100% result under the terms of reference, so the ability to comprehend the finite methodology is of little practical use for the hobbyist, though I'll say again, I'm a great believer in the assimilation of knowledge per se, any and all knowledge.

I believe there are two clearly defined schools on this in any field, not just this hobby. The majority will usually opt for understanding what they need to do to reach a satisfactory conclusion, rather than study the mechanics and associated theories as to how finitely. They only want to know what to do, and as little of the why as possible! I confess to a degree of cyniscism in such matters, for like you Graham I expended some time in the teaching profession at college level, from whence it's difficult to emerge without such traits.

I think that we have served a useful purpose with this simple discussion, by highlighting that there are two degrees of comprehension, the first level for doer's and the second for the curious! Providing we recognise the needs of both wherever possible the goals of sharing information for the common good will prevail.

Chi
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Post by co2 »

Thanks again for all this information I can appreciate these weren’t done in 5 minutes.
I also appreciate that the meter readings are not godsend

But again it is very complex and I can understand why people put the meters away or don’t even bother getting them not knowing the benefits in health that comes with high orp.

I believe orp can be viewed simply or very complex.

Reducers.
Filtration has come along way the last few years and will have greatly improved orp in many ponds.

Duncen you said that if water could be raised naturally to around 450mlv it could be used in nuking parasites and bacteria achieving the same as chemical orp.

Orp has a fixed relation ship with ph.
If you are prepared to go low enough you would achieve this.
What kills the filter in a ph crash the high orp or the lack of carbonates?


Pp and ozone are very powerful oxidizers which reflect in the orp reading.
Hydrogen peroxide is also a very powerful oxidizes yet this drops the orp reading in the pond.
O2 gets a lot of credit for raising orp but I don’t believe it is because of its oxidizing capabilities.
If b weed is photosynthesizing in daylight hours with o2 possibly past saturation point why does orp plummet.


Chi very good point
I have a 3 pod water softener / pretreatment system, consisting of 1 x 5u sediment, 1 x 5u GAC and 1 x 5u carbon block of the highest possible quality. The output is then fed to a 3 membrane RO system, producing water between 1 and 5 TDS, GH and KH are so low as to be immeasurable, PH around 5.8 to 6.0.

The ORP/REDOX of this water measured at the outlet from the RO system is 400 to 420, need I say more?


Ok chi I did say that ph has a fixed relationship with orp. In the thread heading I also said influencing factors.
I have no doubt that the reading are correct but the water has not been through the filter to get the byproduct of the buffering and bacterial activity so would you be so kind as to ad some co2 and come back with the reading please.
I hope you realize if the kh is non existent it will not work
But this should explain where the free radicals come from.

Regards
John
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Post by Fish4Friends »

Hi All

Not precisely sure where people want to go with this thread, As Duncan has pointed out everything regarding our water chemistry revolves around the redox process and as pointed out basic tests are more than adequate for the maintenance of water conditions that will maintain a compatible environment for our Koi

As stated by Chita "Whilst OHMS law in and of itself is a simple equation, the understanding required to extrapolate it's various resultant outputs per input is not always so. And again as stated previously, such excursions are unnecessary for calculation purposes as this is all taken care of by design and or onboard firmware. The boffins have without doubt made allowances for numerous such factors during the design of the equipment, they being well aware of numerous related aspects of water composition. I would expect the manufacturers of Barbie doll's to get that simple bit right, it being hardly serious science"

The first part I agree with totally, Ohms law is simple the resultants are not! the second is a debatable point if you are referring to the units mentioned by Duncan that cost in the £k bracket then yes they have the control but the units sold to the hobby market unless used in a very fine tolerance range are inherently inaccurate, it is only in the very latest models that incorporate a temperature sensor within the electrode head that even an incorrect temp would throw the readings out, as to the last unfortunately when you add electronics to water management it is "serious science"

As you said when you have a 20' goal 1" in or centre it is immaterial, but hit the post at the edge of parameters and it becomes a 50/50 chance of being right/wrong

Let me try illustrate the problem by one simple example, I am sure we all understand that the ionic process, redox involves the transfer of one or more electrons between the compounds interacting, if we introduce a stream of "free electrons" that are captured by the recipient compound, what happens to the donor electrons from the anion?
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Post by chita »

Hi guys, firstly Graham, I think as I may have said previously, there is I'm sure a group who would wish to advance their knowledge beyond the level required to perform the necessary tests. I had never intended to argue otherwise, but simply wished to maintain awareness that a simplistic aproach to advice should be run in parallel at least.

If this is an area where you feel you have more in depth knowledge to share, and are prepared to do so I consider that admirable. I have just so much time to give and decided some time ago that keeping advice simple helped more people with the basics, and quickly. Your aproach offers an opportunity for those who wish to take it forward, a superb chance to advance one's education for free.

Graham, I wasn't aware that anyone made meters these days without temp compensation, I shall check my own but assumed it had compensation, certainly all of my other meters do.

As the only thing measured in water by all of these meters, be they PH, TDS, ORP or others is conductivity at very low voltage / current levels, I had not considered the process itself to be advanced science in that respect, although of course if one requires to understand the processes in depth it could become very scientific. The means by which the various products/results are derived is certainly very complex, as are the algorythms and resultant compromises deployed in the designs.

John, I don't have access to co2, but I take your point, however with the amount of agitation / current flows etc going on in my system it gasses off very quickly anyway. Which has in the past caused me some difficulty with PH!

I have been saying for a few years that PH and ORP are very closely linked, the fact is now being understood by more keepers, I'm pleased to see your interest, this is an area of education which will improve keeping skills.

As I've said to Graham though, if I'm asked for advice I prefer to dispense it at a simple level for the reasons stated, and of course it takes more time to make the scientific arguments in an understandable way!

I touch type at around 40+ words a minute but not when I'm thinking at the levels required for scientific discussion! My surface level advice can be disseminated in minutes, so I'll continue in that vein, but will follow advanced threads in silence until I think I have some valid input.

must visit the office now!

Chi
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Post by Gazza »

Yes lets keep it simple for Muppet's like me :? :shock:
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