下面这篇是KOI National上介绍ORP的帖子。未必很准确，但容易看懂。我的节选翻译其实也够用了，列出原文以示对原作者的尊重。 3PgiV%]
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Introduction Y!nxHRE
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No, I am not talking about an Optional Retirement Program. That is an ORP you might find discussed in AARP’s magazine. We are discussing Oxidation Reduction Potential. Boy, that was a mouthful. What is it? Do I have to be a rocket scientist to understand it? Is it anything of real interest for the average nishikigoi keeper? No, you do NOT have to be rocket scientist to have a working knowledge of ORP for our hobby. ORP as one more tool you can use to care for your Living Jewels. 8oVQ:' 6
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What is ORP? )ND%MYJSq
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ORP is one more those three letter acronyms (TLAs) you get to learn when you read books and magazines about nishikigoi keeping. Simply put, ORP is an indication of how free the water is from organic pollution. In general, cleaner, less polluted, water is better for our nishikigoi. Cleaner water means our nishikigoi can spend their energy on growth and skin quality. They will not have to spend energy trying to overcome poor water conditions. nc Cgc5uP
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Oxidation and reduction were originally thought of as the adding or removing oxygen from another material. This is like adding oxygen to iron to create rust. Now oxidation and reduction are thought of more in terms of the ability to steal an electron (oxidation), or to give up an electron (reduction). '98 0.
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How ORP is Measured Tye[ iJ
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OK, so how do we measure ORP? ORP is about the ability to move electrons. Therefore an ORP meter uses a special probe in the water to measure the potential for moving electrons in the water. This potential is displayed by the ORP meter in millivolts. d yN Kok#
Personally I use an ORP meter that I can calibrate. I follow the manufacturer’s instructions on how to clean the probe and calibrate the meter. I definitely clean and recalibrate before any chemical treatment such as the use of potassium permanganate. I want to know the impact of the dose, not just the theoretical calculated impact. Neither the nishikigoi nor I like surprises when it comes to pond chemistry. Uth H
ORP Levels afNqK~
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Can ORP be too high in a pond? Can the water be too clean? Simple answer: yep. Water can indeed be too clean or oxidative for our fish. In our pond we are NOT trying to create sterile water. Sterile water means no filter bacteria, no algae, and no fish. Bad karma. Bad joss. No thanks. K>x+*UPL
Here are some ORP ranges you might see in a nishikigoi pond and what they can indicate: 8,m3] Lg
<120mv: The water is very polluted. The pond filtration and aeration has not kept up with the organic load. mf\eg`'4?
120-200mv: The water is polluted. The pond filtration and aeration is struggling to keep up with the organic load. =
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200-300mv: The water is relative clean. The pond filtration and aeration are keeping up with the organic load. ()+PP}:$A
300-400mv: The water is extremely clean. The pond filtration and aeration are more than keeping up with the load. This should be the target range for all nishikigoi ponds. jDwLzvM O
400-500mv: This range may be too oxidative for long range good nishikigoi health. May indicate presence of a chemical oxidizer such as potassium permanganate, chlorine, or ozone. !.}ZlA
500-550mv: Very oxidative water suitable for killing parasites. Exposure should not be longer than 8 hours. kvo V?<!
550-650mv: Too oxidative for nishikigoi long term or short term. ;LjTsF'
650-700mv: In this range bacteria are killed within a few seconds and the water is considered sterile enough to be potable. gV\{Qo j
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Items that Impact ORP Readings MR{JMo=r
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There are several factors that will change the ORP level of the pond water. quGv q"Y>
Organic Load: The most obvious thing that will change the ORP readings is the absence or presence of organic pollution. After all, for most of us hobbyists, this is one of the key reasons we purchased and use an ORP meter. ~R!M.gY[rK
Dissolved Oxygen: Remember how we said that originally ORP was thought of as the adding or removing or oxygen to another substance. If we increase the dissolved oxygen levels in the pond, the ORP values will go up. This is one of the reasons folks always hear me preaching for more aeration. -4I Hs=`;I
pH: ORP moves inversely with pH changes. If the pH drops, the ORP levels go up. Bring up the pH, the ORP levels decrease. For example, if your pond ORP is 400mv or higher and there is no oxidizing chemical present, double check the water pH. The pH might be lower than you think it is and lower than you want it to be. 2S^:fm}
Calibrated Meter: Sounds like a no-brainer. You need a meter that has been calibrated and has good batteries, or an AC adapter. A inaccurate meter might be more dangerous than no meter at all if you are using the meter readings to dose oxidizing chemicals. Vv Se`E*
Using ORP $wBF'|eU
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There are many practical uses of ORP for the average nishikigoi hobbyists. ?0%3~E`l:
Checking Filtration: Measure the ORP of a stable pond system. This will tell you how well the pond’s filtration and aeration are handling the load. Expand the filtration and aeration as needed. You can monitor the ORP over time to see if there is any indication that with a growing load (i.e., larger fish, more fish) the pond system is nearing its current limits. {Jx -Zo>'
Measuring Pond Treatments: You can ORP reading to help you perform a pond treatment for parasites with an oxidizer such potassium permanganate. Slowly add the chemical and constantly monitor the ORP levels using a calibrated meter. Bring the ORP level to the target level for the target duration. h]{V /
Checking Dechlorination: Chlorine is one of the most potent oxidizer chemicals available. That is why it is used by government agencies to provide potable water to your home. As koi keeper we do not want the chlorinated water (ORP typically around 650mv) to drive up the pond’s ORP. We can use the ORP readings to add enough dechlorinating chemical, such as sodium thiosulphate, to just offset the impact of the chlorine. Ideally, when all the new water has been added, the ORP is the same, or only slightly higher, than before the new water was added. ?n0Z4 8%
Summary >&g^ `
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ORP readings give you a snapshot of the pollution levels in the pond system. ORP is measured in millivolts using an ORP meter. ORP readings can help you decide if the filtration and aeration should be expanded or the load should be reduced. The readings can also help you more accurately use oxidizing chemicals for parasite treatments. ORP is simply one more tool you can use to better plan and maintain the home of your Living Jewels.
