Hi all
I think we all agree that a higher orp is better for fish health
I would appreciate your views opinions knowledge on orp.
Its relation ship with other parameters.
To get a better picture of how it all fits together to create a balance which we and the koi all benefit.
I feel the complexities of orp leaves it to be an underutilized tool because of its complex structure so to speak.
So for people like me with very little understanding of water chemistry.
Also you who do understand the chemical aspects and the relation ship.
Where does orp come from?
How do we achieve this?
And is there a negative cost to one or more of the other water parameters.
Is there an easier solution to understand orp.
Is how we perceive orp holding us back.
So come on replies from all levels appreciated.
Regards
John.
Thanks graham
ORP or Redox as it is called, stands for "Oxidation Reduction Potential" and is a measure of the waters oxidation potential in mV (millivolts). Like TDS, it can tell you how polluted the pond is with organic material. The more organic load on the system the lower the mV reading will be. In fact, usually as the TDS goes up the ORP will usually descend.
A poor pond with low oxygen saturation and high organics will have a low reading - around 100-150 mV. A well maintained pond with low organics and high oxygen saturation will be higher, how much higher, will depend on system cleanliness and partial water changes performed and O2 saturation, the more the better. Also, the stocking and feeding levels will reflect on ORP. Let’s look at it in more detail.
There is no easy way to explain this as REDOX or ORP is one of the most common but also the most difficult chemical reactions to explain.
ORP stands for "Oxidation Reduction Potential" specifically known as “REDOXâ€Â
Hi John,
As you will see from the link Dunc has dome i like a bit of ORP
I have mine rigged up 24/7/365 so i can just pop my head in and see whats what,if its a bit low or has changed i know something is going on so for that its a great tool.
Do you already measure for ORP and if so what type of reading are you getting i am currently running at 325.
Hi John, we can be assured of one thing from your post, you realise ORP/REDOX is not simplistic! It can however be simplified without aquiring a science degree, Duncan has gone some way in that direction, there's little constructive to add really, but I'll try.
As per my comments in the thread Duncan linked to, the first thing the user must grasp is just how damn sensitive these testers are. ORP/REDOX meters are probably the most sensitive devices you will experience in your lifetime. This sensitivity stems from the requirement for the measurement of a wide range of possible contaminants, in an extremely variable environment, and indeed compound reactions to multiples of same. Imagine a single readout "health" monitor in a hospital, this would have to interpret B.P, Temp, heart rate and lung efficiency simultaneously. It would then have to apply a math's algorythm, finally allowing it to display the results as a single readout summary as it related to your health/condition!
That's an ORP meter, but obviously geared for water testing.
For simplicity I tend to advise others that ORP testing provides a summary of the other key factors in water keeping. Somewhat as in accounting a simplified presentation or "summary" is created to allow normal brains to comprehend the overall state of affairs.
So, TDS, (or EC) D.O, GH, KH, P.H and Temp will all effect ORP.
Change any one even slightly and ORP will fluctuate, so if you consider the events in an average pond during the course of the day, you might begin to understand the reason(s) for ORP meter swings. They are anything but random, each being a reaction to some change, no matter how small in the water.
Additionally air bubbles and water currents/movements will cause swings, hence my dwelling on the need to find the best possible location for the probe, or create one as discussed. We must first address the location, minimising outside effects such as air bubbles or excess water turbulence. Only then can we begin to "learn" what the meter is telling us, it really is a language, but easy to learn if one tries.
I can now tell if my koi have been given "treats" by the family whilst I'm at the office. Just a few extra pellets or a small handfull of prawns and the ORP drops significantly, by which I mean 10 to 20 points. This to me having created a stable environment for my probe is a very significant change. A few leaves in the pond and left for a day or two will do the same, so assuming a good reading of 320 to 350, unless you see a swing of 40 or so don't panic. My own reading at this time of year varies between 350 and 370, which is the highest unaided reading I have personally ever seen.
I hope you find a glimmer of light in the responses you have received to your query, good luck with your advancement in the hobby/obsession.
Can I seriously ask a couple of questions? There is no intent to "find fault or trickery" but possibly add a new angle, for our water chemistry.
Have you ever looked at the fact that water is a dielectric, this means that the water itself has a profound effect on electronic measurement (one of the reasons I believe an ORP meter takes time to stabilise) it in the distilled form has K of 80 [MV/m] (I suspect RO is very similar, except for the contribution of dissolved gasses which are not present in DW) [not having an RO unit I cannot confirm this] and being a liquid has what is termed "self healing" so you have breakdown, reduction in voltage to maintain current flow, followed by self repair needing an increase in voltage to break the dielectric threshold again until you reach "equilibrium" on voltage pressure/current flow!
With respect to dissolved/suspended solids have you looked at the "positive" ion or cation or a neutral "bound" material (cellulose) where the absence of free (loose) electrons should provide an increase not a drop for readings as the redox process should not be in process with these compounds, therefore limiting electron flow (current) as these should be nearer insulators than conductors (relatively)
I was waiting for Chi to pop in and help as always a great response thanks Chi
As Chi has explained they can move about a bit but at least if we have learned what the "norm" is we know whats going on.
I have posted a picture of my ORP tonight this was after doing my maintenance and some food going in......and as they where hungry a bit of extra food went in
Seriously not trying to cause confusion, but as Duncan has pointed out within both the reference thread and this, most of the reactions within the pond with GH, KH, pH dH are all dependent on the addition/loss of an electron (or more 2, 3) so I am asking if the water itself is being taken into account (especially for electronic measurements) also where the "positive charge particles" (deficient of electrons) have an effect? On these readings, the final part was in reference to compounds that are considered neutral or have a tight atomic bond (normally considered "insulators") affect the readings?
Wow firstly thanks for thee great response.
I rushed this post of before going to work and not really meaning to put most of the emphasis on orp but to encourage a topic on how and why all the other parameters ph, kh,co2,o2, have an influence on the reading.
Been having a great chat with graham these last weeks. Which brought this post into being.
Duncan it seems a long with the rest of us you have a high regard for orp but are not too keen on the meters idiosyncrasies in picking up every thing.
If I ask enough questions does this mean I will be able to print your book of for free lol.
All good replies which I expected from the members who posted.
O2 is mentioned in being the main contributor in having a high orp
If this is the case why in winter an unheated pond does the orp reading not shoot through the roof. ? Combined with little organic loading. Should increase this still further.
Duncan, gazza and chi have all stated that lowering the hardness of the water has raised the orp reading.
What would you say if I said orp has a fixed relationship with ph.?
Gazza my orp is high but then again I really need to get some koi lol
Chi you probably have the best knowledge and experience of us all and even you know the complexities of the meter readings. These need simplifying so we all have a grasp of them and a better understanding. Which I do think is possible.
Mark stated on the thread that he had a reading of 400 plus. Why did you disbelieve him as far as I am aware he was adding bacterial additives not chemical?
Thanks again
John
Graham I think I see where you’re coming from.
Which reflects how we perceive orp.
a. A high orp is a measurement of how clean the water is.
b. A high orp is the waters ability to keep itself clean.
Two similar answers but with different meanings.
