Ozone and its use in Koi keeping ................ F.A.Q. ........
WHAT IS OZONE?
Ozone gas occurs naturally in the atmosphere. When a molecule of Oxygen, O?, is bound to a third oxygen atom, it becomes Ozone, or 0?. Ozone is an unstable bluish water-soluble gas with a characteristic smell. At low levels it makes the air smell fresh and its colour makes the sky blue. Ozone is the 2nd strongest known oxidiser and the most powerful readily available water sanitiser. It kills bacteria and viruses over 3,000 times faster and is a 50% stronger oxidiser than chlorine. It is unsurpassed for control of many types of common bacteria such as E. Coli and faecal coliforms as well as the de-activation of virus, fungus, mould, mildew and cysts, and it is not carcinogenic.
HOW DOES IT WORK?
Ozone is nature?s way of purifying the air we breathe. As ozone circulates and comes into contact with airborne (or waterborne) pathogens, one of the three oxygen atoms detaches itself from the Ozone molecule, attaches itself to the pollutant and oxidises it and therefore destroys it. Ozone is nature?s way of cleaning our environment.
Ozone is such a strong germicide that only a few micrograms per litre are required to demonstrate germicidal action; it destroys all pathogenic microbes in water. The action of Ozone gas in water is instantaneous and after oxidation, Ozone breaks down into Oxygen, without leaving any toxic by-products or residues.
Ozone is a completely natural disinfectant and steriliser and unlike chlorine, does not produce trihalomethanes or chloroforms in water and unlike other chemical disinfectants such as potassium permanganate leaves no harmful toxins or residues in the water.
Without dispute, scientifically speaking, Ozone is the most effective natural bactericide and viricide of all the disinfecting agents.
HOW DO WE MEASURE THE THE EFFECT OF OZONE ON THE POND WATER?
The Ozone dosing of water is measured in millivolt terms and is expressed as the REDOX or ORP level (Reduction /Oxidation potential) of the water. Normal pond water will have a REDOX level of around 200mv or less. Sterile water has a REDOX level of around 700mv. Some Ozone generators are designed to automatically regulate the ozone dosing to keep the REDOX level at a preset level, normally around 350mv - 380mv in a healthy aquatic environment, so that the water is not sterile or anything like, since it could not then support life.
WHAT IS REDOX REACTION?
A chemical reaction in which electrons are removed from one atom (which is thereby oxidised) and added to another (which is thereby reduced). The movement of electrons is then measured on a millivolt scale.
WHAT IS OXIDISATION?
Oxidisation is the process that causes steel and iron to rust, an apple to shrivel & go brown once cut open and is also responsible for the degeneration or ?rusting? of our bodies, causing cellular breakdown. Oxidisation or oxidative stress has been linked to many degenerative and chronic diseases including heart disease and cancer. It is also responsible for premature ageing. Oxidisation permanently disrupts and damages cell structure, thereby killing simple cellular organisms very quickly. Our beneficial nitrifying bacteria employ the process of oxidation to remove harmful ammonia and nitrite from our pond water by converting Ammonia to Nitrite and then Nitrite to Nitrate. Oxidisation is the process used by chemicals such as potassium permanganate, Chloramine T and Virkon to disinfect our pond water.
WHAT CAUSES OXIDISATION?
Oxidisation is caused by oxygen molecules that are missing an electron, making them unstable. Oxygen cannot exist in this unstable form and has to be stabilised. The molecules collide with healthy, stable molecules be they in inorganic substances such as metals, or organic substances such as living cells and then ?steal? an electron in order to stabilise themselves. This damages and de-stabilises the molecule that they have collided with leaving it now missing an electron itself. The formally healthy molecule is now itself an unstable ?free radical? and will also try to stabilise itself by colliding with another healthy molecule and stealing one of its electrons. This creates a knock-on effect that damages and destroys living cellular structure, and in our pond environment this includes parasites, viruses, bacteria, algae or any other living organism with a simple cellular structure.
IF OZONE KILLS BACTERIA, WHAT ABOUT MY BIO-FILTER - WON?T THAT BE AFFECTED?
Yes - but only beneficially! Pathogens are killed instantly as they pass through the ozone stream in the ozone reactor or protein skimmer, but obviously your nitrosammonas and nitrobacter do not, as they live on your filter media. True, they are free swimming as well, and any that pass through the Ozone system will be destroyed. However, it is a recognised fact that the beneficial filter bacteria have relatively short lives but can multiply very quickly given ideal conditions and it has been scientifically proven (Hueckstedt 1960) that nitrification bacterial populations increase faster in an ozonised system than in a normal non-ozonised system. This is almost certainly because the entire pond environment is cleaner and considerably more aerobic (oxygen rich) in an ozone treated pond, and it is a well known fact that nitrifying bacteria reproduce and perform much better in oxygen rich systems. Also some pathogens are anaerobic (live in a zero or reduced oxygen environment) and in a pond treated with ozone there will be virtually no chance of anaerobic conditions existing. So the high Redox levels of the pond water is of considerable benefit to our friendly bacteria, but is definitely the enemy of pathogens.
Extract from Professor Heuckstedt 1960 on the use of ozone in aquaculture.
?It should be discussed whether ozone treatment and biological activities of bacteria co-operate. The suspicion that by ozone treatment not only the harmful but also the useful bacteria (nitrification bacteria for instance) could be killed is quite obvious. But strange enough this is unfounded. Either these bacteria are not in the free water but mostly at the bottom of the aquarium or on the algae or they grow faster than they die. Probably both versions are correct. It can definitely be said that nitrification bacteria will die faster without ozone than with ozone?
If the Ozone kills only on direct contact in the Ozone reactor -
WHAT KILLS ALGAE AND OTHER ORGANICS THAT DON?T PASS THROUGH THE OZONE STREAM?
Ozone raises the Redox potential of the water substantially. This renders bacteria, algal spores and other organics much more susceptible to oxidisation - to having their cells destroyed or disrupted, even though they are not necessarily in direct contact with Ozone. Put another way, chemically the pond water is far more reactive as it is saturated with Oxygen, and single cell organisms or organisms with a simple cellular structure are easily oxidised and therefore tend to have a shorter life span. Direct contact with Ozone in the Ozone reactor means instant death, the higher Redox of the pond water means cells are easily oxidised (killed) and cannot reproduce effectively so their population decreases.
OK great, but
IF OZONE IS SO STRONG AND EFFECTIVE AT KILLING BACTERIA ETC HOW DO I KNOW ITS NOT GOING TO DAMAGE OR KILL MY KOI?
Simple, the Koi never come into contact with ozone ? remember, the water is treated, or disinfected in a special skimmer or ozone reactor outside the pond environment so we never need to introduce ozone into the pond directly. Any residual ozone produced and not used up in the reactor gasses off to atmosphere and does not get transferred into the pond water.
Ozone treatment leaves ?free radical? oxygen atoms available in the water which are responsible for the oxidisation process and which cause cell damage. Bacteria and protozoan parasites are single cellular organisms so they are relatively easy to kill ? damage or disrupt one cell and you have effectively destroyed the organism. Koi are higher life forms and are made up of many billions of cells (like humans) and can afford to lose one or two, they do so every day naturally. Cells reproduce where necessary throughout their lives so there is no detrimental affect on our Koi as a result of using ozone any more than there would be by using the correct level of any established Koi medication in our ponds.
I?VE BEEN TOLD THAT OZONE MAKES THE WATER STERILE AND CAN MEAN THAT THE KOI?S IMMUNE SYSTEM DETERIORATES AS IT DOESN?T HAVE TO WORK SO HARD ANY MORE?
This is an old argument but is simply not true. In a sterile pond environment, the Redox level is around 700mv - at this level all life would cease to exist in the pond. The ideal Redox level of a Koi pond is around 380mv. At this level pathogen levels are substantially reduced but your koi will be very happy and healthy. Also there is absolutely no scientific evidence that disinfection of pond water by oxidisation, whether this be by ozonisation or chemical additives such as potassium permanganate, chloramine T or Virkon affects the immune systems of fish, including koi.
Remember, we are using ozone to lower the level of pathogens in the water, not eradicate them entirely, which would be virtually impossible ? so the Koi?s immune system still has plenty of work to do when necessary.
In their natural state, in rivers or lakes, each fish has a comparatively massive volume of water in which to live and bacterial loading is much lower than in a man made koi pond. Using ozone simply helps us reproduce nature. It is like attaching your pond to a freshwater stream, with new water flowing in on one side, and old flowing out of the other - effectively continually flushing out the system. Would a koi?s immune system weaken in nature because it is not continually subjected to high bacteria counts? Of course not - quite the reverse!
In our experience of using Ozone systems over the last 8 years we have seen absolutely no evidence that koi removed from an ozone treated pond and moved into a ?conventionally? filtered pond are at any disadvantage, and we see no increase whatsoever in the incidence of disease because of moving koi between these environments.
Marine hobbyists have been using ozone systems to manage fish health for many many years and we do not see any detrimental affects to fish health ? quite the reverse, so why should Koi be different?
This is simply ill informed nonsense from the prophets of doom who simply can?t - or won?t accept ?new? technology, even when it works brilliantly.
CAN I USE AN OZONE SYSTEM IN PLACE OF A CONVENTIONAL FILTER?
No, you should consider an Ozone system to be a part of your overall filtration strategy, as it will not replace either the mechanical or biological elements of your conventional filter, but it will enhance the performance of your existing system thus rendering it far more efficient.
Can I still treat my pond with chemicals? and what happens when I do?
Yes of course, from time to time you made need to use a pond medication for parasites etc. When you do, simply switch off your Ozone generator. Ozone would destroy chemicals in the pond very quickly and would render your treatment useless. When your treatment is complete, switch on again and the Ozone will clear the chemical residue very quickly.
I HAVE HEARD THAT OZONE IS DANGEROUS TO HUMAN HEALTH - IS THIS TRUE?
Ozone is a powerful oxidising agent, and certainly if used carelessly or incorrectly it could be dangerous to health. However the same is true of almost all the chemicals we use in our hobby, even salt. Potassium Permanganate and Chloramine T are powerful oxidising agents and need to be handled and used correctly and definitely not ingested. Similarly Malachite Green, and Formalin are dangerous substances which should not be handled with bare hands. Of course we know this and treat these substances with the respect they deserve. Indeed none of the substances we use in our day to day koi hobby should be ingested, inhaled or come in to contact with bare skin - again common sense.
Similarly we certainly don?t want to breath in high levels of Ozone constantly as it can irritate the respiratory system, and therefore Ozone systems must be specified and installed correctly, with any residual Ozone produced gassing off to atmosphere - not inside your filter house! This is common sense, just as we should always install residual current circuit breaker devices in our electrical circuits anywhere near water - to prevent any chance of electricity and water mixing - which would almost certainly have fatal consequences.
Ozone has been in use as a safe and effective disinfectant for ventilation systems in offices, factories and even ocean going liners since the 2nd world war. It is used in modern bottling plants to disinfect plastic bottles before filling as conventional sterilization methods using steam would damage the containers. It is now commonly used in wineries to disinfect bottles, casks and other equipment. Ozone systems are now also widely used in food production environments to keep food fresh longer and reduce food related odours. Ozone is also being used by some major water authorities to disinfect our drinking water instead of Chlorine simply because it is far more effective and is much, much safer.
Ozone has been used in human medical treatments since the before the first world war. It is, and has been used for the treatment of MRSA and other bacterial issues that do not respond to conventional antibiotics. It is used for the treatment of Arthritis, Rheumatism, Hepatitis, skin lesions, ulceration and for a wide variety of internal infections and disorders. It has even been used as a cancer treatment. It is also now used in dentistry for disinfection, wound cleansing and improved healing.
It is most unlikely that such systems would have been developed or used if there had been an unacceptable human health hazard. Ozone is used in many facets of industry, for many different industrial applications and no-one has ever died or been seriously injured as a result of ozone poisoning! The same cannot be said about most of the other commonly used chemicals that we regularly use in Koi keeping.
World-wide, In over 100 years of ozone usage with some installations generating ozone at a rate of over 250kg/hour there is not a single record of inhalation of ozone causing even a single death - compare this with Hydrogen peroxide, chlorine and other chemical-based disinfectants, biocides and germicides... Even excesses of salt have been the cause of death...
Ozone has a very distinctive sharp, ?fresh? smell which many people identify with a disinfecting agent and it can be detected by the human nose at levels 10 to 30 times lower than that which is recognised as being harmful to human health. In addition, Ozone is very unstable, and once created, immediately begins to decompose back to Oxygen again. This decomposition takes between a matter of several seconds and several minutes. It does not therefore even exist in a ?dangerous? state for a significant time.
We can therefore categorically state that a properly installed Ozone system would be a very safe part of your koi filtration system and one with which there would be no associated health risks whatsoever. The prophets of doom will have to look elsewhere!
CAN I DISPENSE WITH MY UV SYSTEM?
Yes you can. However in practice we find it is best to leave the UV in place if you already have one fitted. Ozone generators have to be serviced from time to time and the UV can serve to keep the water clear whilst the Ozone system is switched off. We would recommend leaving your UV in place if you are using dry air as an input gas. If you are using an oxygen generator then you definitely wont need a UV ever again!
CAN I STILL USE SALT IN MY POND?
Yes, absolutely. The Ozone won?t affect the salt and you will find that protein skimmers produce a lot more foam with salt in the water, so it actually works even more efficiently.
ALL SOUNDS VERY COMPLEX - DO I REALLY NEED AN OZONE SYSTEM?
No, we can?t claim an Ozone system is an essential part of a koi pond filter system, but that?s what was said about bottom drains and vortexes a few years ago. Now very few ?proper? koi ponds are built without these essential items. For the serious koi keeper we would recommend an Ozone system be included as part of the overall filtration strategy. We believe that in the near future, Ozone systems will become just as much of a necessity as a bottom drain.
WHAT DO I NEED TO COMPLETE AN OZONE SYSTEM?
We need several items to build a complete Ozone system, rather like building your own Hi-Fi system. First we must have an Ozone Generator to create the Ozone initially and optionally a Redox controller which enables the system to operate automatically and switch on and off the Ozone supply as required. In most larger systems we then need some kind of Protein Skimmer, ozone reactor or mixing chamber to mix the Ozone produced with the water as efficiently as possible, allow it do ?disinfect? the water, and then remove any residual Ozone before the water is returned to the pond. We can also install an oxygen generator, as Ozone systems utilising oxygen as a feed gas are super efficient. Without doubt however, the most important elements of any Ozone system is the sizing of the Ozone reactor or protein skimmer coupled to correct size of ozone generator and correct installation techniques.
Small ozone systems can be installed with reaction chambers or mixing vessels which can simply be a spare chamber in an existing filter system. With larger air driven systems the ozone reactors need to be much larger as mixing of air/ozone and water is less efficient. To overcome this issue, our larger ozone systems come as standard with oxygen generators so that gas volumes are reduced to a minimum, and the efficiency of any ozone reactor or mixing chamber used will increase dramatically. Oxygen generators can be retro fitted to just about all ozone systems to massively increase efficiency.
THE TECHNOLOGY SOUNDS COMPLEX, ARE THESE SYSTEMS RELIABLE?
Early Ozone generation equipment was not particularly reliable, as the generators produced a lot of heat, and early systems were water cooled. These were large and cumbersome and needed fairly regular maintenance. The latest systems are all air cooled, are far more efficient , use less power and therefore produce less heat energy. These smaller systems use relatively tiny amount of electrical energy and are simple and very reliable devices which are guaranteed one year. There are no moving parts in the generators other than cooling fans and the only maintenance required is an annual clean or replacement of the generator electrodes.
The protein skimmers and ozone reactors have no moving parts (other than adjustable valves) and need no maintenance - not even cleaning.
The only item which needs more regular attention relates to systems utilising Redox controllers where the actual Redox sensor should be cleaned with a soft toothbrush about once per week to prevent it fouling.
Ok, I?m convinced, but how do I choose the right system?
Firstly, you obviously need to know your pond gallonage. From this you can first calculate the size of Ozone generator you will need by using the formulae of between 0.5gm/hour and 1gm/hour of Ozone for every 1000 gallons if using dry air as an input gas. When using oxygen as a feed gas, via an oxygen generator you will only need 0.1gm - 0.2gm of Ozone per 1000 gallons.
We can obviously help by recommending a suitable system for your given application - please e-mail for further information