Monday, October 28, 2013

Integrating AFS with other systems…

Integrating AFS with other systems…


Can I integrate my existing filter with the Anoxic Filtration System?


With this question, I almost have-to answer with a question of my own: Why would you want to? The filtration system that most people use can be cantankerous and creates more work and byproducts than the Anoxic Filtration System does. Once hobbyists start using an AFS they now realize the faults of their existing filtration system and may discontinue the old filtration systems use altogether. The burden from your existing filter may be too much for the Anoxic Filtration System plus the fish load for it to handle. The filtration system that you are using is the nidus of bacteria and will unquestionably create tons (figuratively speaking) of nitrogen waste. The addition of nutrients dumped into the bulk water from this type of filtration equipment would affect the overall systems stability and overall water chemistry. 

On the other hand, the Anoxic Filtration System by facultative anaerobic heterotrophs1 utilizes in a reduction process the incoming nitrogen and in turn, turns it into a gas element, Dinitrogen, N2, which is the most common form of the element nitrogen in normal conditions, which is then released into the atmosphere (Dissimulative Denitrification). Consequently, as defined in the Encyclopedia of Scientific Definitions, if a filtration system is not working properly, then it will not produce Dinitrogen. Nitrogen is a nonmetallic chemical element. It occurs in nature as a colorless, odorless, and tasteless gas. This gas makes up about 78% of the earth's atmosphere by volume. I’m trying hard not to be condescending, but I’ve heard the same tired, old argument parroted over and over so often that my patience wears thin. Nevertheless, I will try again to undergird my point once again.

First, the filtration system that you are using now will unquestionably begin to clog and when that happens, oxygen concentrations become depleted where there is no water flow through the substrate and/or filter medium. Nitrogen is then reduced back into ammonium (Assimilatory Denitrification) in a two-step process by obligate anaerobic heterotrophic bacteria, which becomes problematic to the pond ecosystem. These extremophiles under anaerobic conditions that have developed from a clogged filter will not convert ammonium back into a gas element that is released into the atmosphere. I do not know where hobbyist got the notion, that anaerobic conditions will convert nitrogen into a gas element, but I hope we can clear up this matter right now and here, it does not! It just makes more ammonia / ammonium that your system now has to deal with. This is extremely important because ammonium can be recycled in the filter back to nitrate and either or both nitrate and ammonium can diffuse throughout the filters media, creating an extremely nutrient-rich filter environment and leach into bulk water. The additional ammonium and/or nitrates that leach into the ecosystem become a new food source for cyanobacteria and algae alike.

Therefore, it should now be extremely clear just what classes of bacteria exist, where and why, and what they can accomplish. However, in most cases, our ponds contain more bio-load than what existing microbes can adequately process into an overall balanced environment within the pond biotope and available space on the filters medium. It can technically be said that no matter what type or size of filtration that most hobbyists use, the microbial population in the filter will be in equilibrium and/or balance state with its supply of foodstuffs. But clogging will hider this equilibrium and swings its chemistry in the negative direction if reductions of those foodstuffs aren’t reduced very quickly. Because once nutrient load exceeds the balanced state of the filtration system, (and that degree of balance depends upon what class and the number of microbes exist in the filter itself) further nutrient results in both the filter and the bulk water. Of course, this relates to the bacterium that inhabits the filtration system. An AFS should not subsidize an inadequate filtration system but the two should work together but this is hardly the case because why would you need a AFS in the first place if you existing filter was doing its job?

This is a true photo taken from a pond of 1600-gals here in the US of A with almost 50 Koi in it using an AFS ranging in size from 14-30".

 Second, under the same conditions mentioned above, if your existing filtration system is one of those that clog easily, two colorless, flammable, poisonous gasses, methane (CH4), and hydrogen sulfide gas (H2S) are then created. These two gas elements have been proven to degrade water quality significantly. In addition, forming a weak acid called hydrosulfuric acid and blackening of the substrate can occur due to the lack of free-oxygen in the substrate.

Furthermore, methane with ammonia will produce hydrogen cyanide (HCN). Hydrogen cyanide, also called hydrocyanic acid and prussic acid is extremely poisonous to humans and aquatic animals alike. Numerous plant and aquatic animal diseases can be related to such gasses along with premature death, with the hobbyists not knowing or understanding why!

If integrating the two systems is what you really want, just remember that the results you may get from doing so may not be the results that you really were looking for. You also must keep in mind the extra work your existing filter places on you. Invoking Occam’s razor, you must ask yourself this question: Do I really need to spend more time doing maintenance on a complex filtration system just to keep my aquatic animals alive and healthy? A good example is Brian Woodcock in my blog only took twenty minutes to clean his AFS. If the answer to this question is yes, then integrating the two-filtration system is for you. However, if your answer is a definite no, then the Anoxic Filtration System will be your forte. 

 I have assiduously designed this system as a stand-alone filtration system. It is more than capable of handling almost any bio-load that a hobbyist may place upon it with the capabilities of expanding it by adding more Biocenosis baskets if needed. Integrating this system with another system is redundant but not useless. However, again that choice will only be up to you, as each individual will have to make that decision on a priority basis. My thought on this whole thing is to invest in a better prefilter and save your money for superior Koi. 

Anoxic filters are a much-abused filter! Why? Because once hobbyists find out how they can push them with bigger animal loads, then they do! Please do not do this, just because you can doesn’t mean you have to. I see this all the time when people use AFS and before you know it they abuse what they have to the point of being ridiculously overstocked ponds. I did not design this filter so hobbyists could abuses their animals, it was design to save their animals’ from the very thing that gets hobbyists into trouble in the first place…overstocking!!!!

1: Ana ["e]robic bacteria. They are called facultative ana ["e] robia when able to live either in the presence or absence of free oxygen; obligate, or obligatory, ana ["e] robia when they thrive only in its absence.

 [Ed:  Please Note: Yes you can integrate the Anoxic Filter with other filtration systems and the effectiveness of the Anoxic Filter or that which it is integrated with will be unaffected of their performance. If anything; the Anoxic Filter will enhance the overall stability of the entire system and cleaner water along with Nitrate reduction abilities will be its outcome.]

Saturday, October 19, 2013

Today after 2 years and 132 days my water parameters are zero ammonia, zero nitrite and 7mg/l nitrate. All this with 50 large Koi being feed 450 grams of 43% protein food a day. Who says Anoxic filtration doesn’t work ?

This was posted on Koi 4 U  October 15, 2013 By: David.
So I thought it was time for another look at this thread & filter. 
Over two years ago I decided to try out the Anoxic filter. At this time I was running a stainless steel EA system with an Answer fitted into the first tank and then Jap Mat in the second. With a pond of 45,000 lts and about 50 large Koi I was having difficulty with all the parameters. Next step was to try Kaldness K1, so I fitted a third tank and removed the Jap mat and purchased 350 lts of K1. Things did improve but I was unable to feed more e than 350 rams of 34% protein food a day. On top of this I had very high levels of nitrates through not changing enough water but I’m on a water meter and am paying 5 euro’s a cubic meter.

Having also spent some time reading through Dr Novak’s PDFs I thought I’d give it a trial. This involved building a 3,000 lts filter to house the baskets. As it was a trial the filter was built indoors and is 1 meter lower than the pond so it also needed pumps and level switches. These of course need money and electricity but it’s only short term!!

Finding the correct cat litter was a problem but after many trials with dissolving cat litter, I made 39 biocensis baskets and started the filter running. This improved the water parameters but very slowly as the K1 is producing nitrates at a fast rate. Over the next 3 months I removed the K1 at the rate of 5 litres a day. 

So at last after 3 months I have a mature Anoxic filter but I have a pond full of hungry Koi and 45,000 lts of pond water with over 200 mg/l of nitrates! Time for the Anoxic filter to prove itself. 

To help with the detritus problem I have removed the Answer and tanks and fitted a Cetus sieve. This is of course not perfect as it has a 300 micron screen and so some detritus still gets through. Because of the fast flow through the filter the waste tends to spread out across the floor of the filter. The detritus doesn’t go rotten and just seems to turn to “mulm” just like it does in a settlement chamber as used by some Koi keepers. 

Today after 2 years and 132 days my water parameters are zero ammonia, zero nitrite and 7mg/l nitrate. All this with 50 large Koi being feed 450 grams of 43% protein food a day. Who says Anoxic filtration doesn’t work ?

Plans for next year is to build a new filter outside next to the pond and replace all the pumps with an Airlift. Roll-on Spring time.

Any questions ? 

Rosewood Tetra Pond Floating Foodsticks, 450 g (1 lb), costing £9.28 a bag. That’s a lot of food a day and the AFS is handling it with no problems. 200-ppm of Nitrates is one of the highest levels of Nitrates I have seen/heard yet in a hobbyist pond and the AFS has taken that down to 7-ppm…WOW!

Thursday, October 17, 2013

Salt and no vinegar: An overview on salt, sodium chloride, by: Duncan Griffiths

Salt is one of life’s mainstay spices but is not a mythical panaceum for diseases or keeping bacteria at bay or a solution to solve all problems related to Koi heath.  

In this article that I have included in my blog, it hits many good and true points that hobbyist should read and take note on. Many think that salt is a good prophylactic and will keep parasites at bay via implosion of the parasites in fresh water systems and exploding in saltwater systems. But this is only true in a quick dip of salt solution only and in the long term the parasites will just adjust to any salt solution you put them in eventually and the Koi will be no better off for it. I have even heard those that should know better like MD’s tell hobbyist that salt will implode parasites if you keep a constant level of salt in your ponds…this is not true and has no scientific merit backing it up! Please do not fall into this misconception that salt will protect your Koi, in the long run it does more harm than good, and this has been scientifically proven.

Undergraduate students from the University of Michigan have conducted an assortment of scientific research on salinity tolerance of Cyprinid. The experiments performed were to gather information involving salinity tolerances and preferences. The metabolic rate of Cyprinid was measured at 10-ppt sodium chloride levels (saltwater aquaria has a specific gravities of 1.020-1.025, which is about 27.30-33.75ppt.) and their metabolic rate in freshwater was to be their comparison. It was establish that at 18° C. (65° F.); Cyprinid would need a hundred percent more oxygen per milligram of body weight than it would in just plain freshwater. In many books and magazines, it states, “The salt will also help relieve some of the metabolic stress on the fish so its immune system can fight off bad bacteria.” This statement by the studies conducted by the undergraduates is very misleading and inaccurate. Metabolic rates of Cyprinidae do not decrease, but increase, as salt concentrations elevate. After all what animal currently: Breathes heavier, drinks water continuously, when it normally doesn’t drink water at all and needs more oxygen to sustain itself when it is supposed to be “relaxed”?

If you’re using salt to lessen Nitrites toxicity in your pond then you have a filtration problem that must be rectified A.s.a.p.; not putting a Band-Aid on it by using salt like so many hobbyist do. In this case the hobbyist must realize that their filter is inadequate or they just have too many animals for the body of water they are trying to keep them in.

 If bacterial reasons are why you are using salt then you are definitely under the same misconception that salt will lessen the number of cells that are harmful to our animals. Bacteria are very resilient and will adapt to their environment and become super-bugs. You would be better off buying a bigger and better UV sterilizer than adding salt to your pond. UV sterilizers or Ozone will eradicate bacteria if used properly, better than any salt solution will, this is a proven fact! It is also a proven fact that the two pieces of equipment mentioned above will improve water clarity, redox quality and lower TDS; salt on the other hand will do none of these.

Salt will have no negative effects on an AFS at all and can be used in conjunction with medication if need be. Like all medications, commonsense should be applied when using a medication with any filter when that medication could or would negatively affect the bacteria and the nitrogen cycle.

I do not know who Duncan Griffiths is (I think he’s from the UK), but he would get an A+ in my class for telling it like it is. He has but this article on the internet for public viewing and I think it deserves merit in my blog so others can read it.



Disclaimer: This article is for educational purposes only and not for monetary value. I do not warrant or assume any legal liability or responsibility for its contents.

Salt and no vinegar: An overview on salt, sodium chloride, by: Duncan Griffiths 

Many koi keepers have accepted salt in the koi pond system as therapeutic and have used it on a day-to-day basis for many years. Salt is known to be a strong bactericide and is used in many medical conditions both in human health care and in small and large animal vet practices.

In the koi hobby it is used as a prophylactic long-term additive to the koi's closed circuit environment.  It is believed that in maintaining a constant low-level dose of salt helps with stress in the fish, maintains a good immune system (stimulating mucus production), and keeps bacteria both Aeromonas and Pseudomonas, to small numbers. It also is believed to help keep ectoparasites low in numbers and finally helps a koi dealing with toxicity from high or constant nitrite levels or other chemical imbalances either internal or external. Whilst some of the above points may be true some are not, and even some that do have some basis of fact, there can however be equally logical reasons which make the case in the opposite direction.


It’s a proven fact that salt does help with stress in koi; in the short term it's very successful for this purpose. So one could draw the conclusion that it is no bad idea to keep koi in a permanent low-level long-term solution. This is not however the case. The koi should not be subject to permanent long-term stress. This tactic just glosses over a basic inadequacy in the koi keepers system, either poor husbandry or poor and inadequate filtration. In the short term this is an appropriate course of action, above five to six weeks it is not. A low-level concentration of salt in the long-term will not protect the koi from a constant barrage of stress the koi will in the end succumb.  But however if the koi's habitat has excellent water quality there is no need for the salt being in place.


The koi's immune system is a very complex mechanism.  The koi’s first line of defense from external threats is the mucus layer of the cuticle, which is produced by the gills and by goblet cells located in the epidermis. The cuticle contains antibodies, which help the koi defend against disease. Also contained in the cuticle is unwanted debris from the cells of the fish, which is what parasites find so irresistible. So one could argue if we could stimulate the koi to over produce mucus we could increase its immune system. The trouble with this theory is, there has to be a greater understanding as to what circumstances cause the over production of mucus. The koi can over produce mucus for a variety of reasons but to demonstrate the point we will take parasitic involvement. When parasites invade, it causes immense irritation to the koi.  If on the first few attempts to be rid of this irritation the fish is not successful the koi will begin to over produce mucus. This is an involuntary action on the part of the koi. If the parasitic condition does not resolve itself, which of course it may not, without medication, the koi will continue to over produce mucus. The next step is the koi gets covered in the familiar slime disease, but by now the koi’s immune system is going into reverse. Why?
There comes a point in the koi's battle against the irritation whilst it is over producing mucus that the gill lamella gets clogged in its own mucus as a direct result of the excessive production. This in turn impedes the koi's ability to take in an adequate oxygen supply; the knock on effect of this is the koi gets deprived of oxygen by its own making. When the koi's oxygen level drops the immune system begins to degrade. Its ability to fight the parasite diminishes and the parasite takes this opportunity to overrun the fish. The fish then gets weaker and weaker until in the end it simply gives in and dies. Salt in a koi pond is an irritation to the koi, which is why it causes over production of mucus and this is the desired effect and reasoning for its continual use. If a parasite is present without suitable medication to cure the parasitic irritation the salt can make a bad situation worst.

I have on occasion found salt to be the one last piece of the jigsaw that pushed an already sick fish over the edge by further encouraging over production of mucus, that in turn impedes the fish's ability to respire, plus, salt already depletes oxygen, not by much but it is another factor in the koi's inability to take up adequate oxygen. These factors all come together to finish the fish. So you can see from this, to subject a koi to long-term exposure to salt is in itself causing it long-term irritation and therefore a form of long-term suffering. That’s the price of adding salt to get a*good* mucus layer and *immune* system. Having said all that salt as a treatment for koi is usually more of a benefit.  The type of drawback I have just indicated of salt pushing a sick fish over the edge is rare but does happen on occasion. And it’s a valid point that is worth bearing in mind when contemplating the long-term use of salt.


The case for lowering bacteria is a complex one and is open to many interpretations. Many people say you can’t have a completely bacteria free system for many reasons, this reminds me of a strain of bacteria that learnt to survive deep on the sea bed around hot springs gushing up sulphur from volcano's under the sea bed .

1. In an ideal world even if the bacteria count in the water is nil there will always be bacteria on the fish.
2. The fish will always be producing bacteria in there waste product.
3. You have air bourn contamination including bird droppings etc.
4. Bacteria from plants in the pond the list could be endless.

It’s a recognized fact that salt does kill bacteria, what types and how many, will be the topic of many a hot debate. If you buy into the fact that salt kills bacteria, you also have to buy into the fact that to keep salt in the pond on a permanent basis there must be no half way measure's, that salt either kills or it does not. (Salt kills all or salt kills nothing) if your uncertain what strains are left and how many what was the point?

  I know the advanced hobbyist will make it his mission in life to find the answer to this question, but the everyday hobbyist will probably never know. He will simply keep adding salt thinking this is an appropriate course of action rightly or wrongly based on what he has observed some other folks in the hobby do. A simplistic view true enough, but if you accept the last few statements you could argue the fact it might not be possible to lower the bacterial count with salt alone. BUT again it's not quite that simple. I am reminded of a saying, "Man rules the earth" some say it’s the “insect” others “mammals”. Make no mistake this planet belongs to Bacteria! The bacterial evolutionary trail is impressive to say the least.
Bacteria evolve to changes in its environment faster than any other organism; the evolution time scale for bacteria when it is forced to adapt to change is measured in a year or two probably less, not hundreds and thousands of years as it is with the animal kingdom. We share this planet with bacteria not because bacteria allow us; no matter how effective bacteria are at the survival game our immune system is far better in most cases.

I say most cases because we still have to live with bacterial strains that are ever present and are a very real threat to humans and animals and our immune systems have not yet learned to combat such strains. So it seems that bacteria are better able to adapt in evolutionary terms than we are. With this in mind you will have to assume that there will be bacteria in the pond system for which salt poses no threat. And for the strains that are effected to constant levels of salinity and do succumb readily, these strains did not magically appear in the pond system and are likely supplied to the pond from readily available sources on a continual basis. And upon entering the system and continually meeting an opponent like salt, they should eventually adapt, and ultimately overcome the very thing you put in place to stop them.  If bacteria can overcome antibiotics, bacteria can and should reign over salt.


Salt has been used for eradication and control of parasites, well longer than I care to remember, and it does seem by many to be very effective for this purpose. Although personally speaking I have yet to find a case of parasitic outbreak that salt has cured for ME[Ed: I also must agree here with this statement that salt gives hobbyists a false sense of security.]. But then again the author is known for taking a more direct approach to parasitic outbreaks thanks to Mr. Potassium permanganate and Mr. Chloramine T.  When using salt for parasitic control the salt acts like a piece of blotting paper soaking up water, this process is called osmosis.

Osmosis and osmotic shock

A term for the transfer of a fluid through a membrane from a low to a higher concentration solution. In ordinary circumstances in a fresh water system when salt is added to the system lets say 0.6% salinity any fresh water of nil or low salinity migrates to the higher salinity until the concentration equalizes. However on occasion this appears to work in the koi keeper's favor for a couple of reasons one of which will be discussed in the very next section. But from the parasitic point of view, as salinity is increased in the koi pond the fluid in the body of the parasite being of a lower value to the outside salinity begins to migrate to the outside of its cell walls in an effort to equalize the pressure difference. Thus dehydrating (crenates) the parasite, and destroying it.

The object of the game in this instance is to increase the salinity very quickly, in fact as fast as the koi can withstand. So as to create an unequal concentration between the inside body fluid of the parasite, and the surrounding water. The cell cannot adjust in time to stop the loss of body fluids. The same is also true of saltwater fish and its parasites but in reverse. If you dip a saltwater species' suffering from parasites in fresh water the fresh water migrates into the cell of the parasite, as the fluids of the parasite is of a higher salinity, and as the parasite inflates with fluid its cell wall is breached.

So you could say the fresh water parasite implodes and the saltwater parasite explodes. So from this you will observe that the key to parasite control is to move upward in salinity as quick as is safe for the koi. If the occasion arise to increase salinity slowly which is often the case with low permanent maintenance salt doses the effect is lost. The protozoan has time to adjust (exchanging its body fluid for one of a higher salinity). Additionally the concentration difference is a lot less in a lower salinity, so a lot less osmosis takes place. I have personally seen flukes, trichodina and costia living quite happy and oblivious to the fact that their environment was 0.9% salinity. The koi does not suffer from these adverse effects of salt osmosis because of its complex osmoregulatory system, which sets up a defense against the exchange of fluids. But there are circumstances in koi where this system fails and that is the subject of further sections.


The koi has a very complex system for the exchange of salts, body fluids, the intake of minerals, which it constantly exchanges and processes, the process that controls all this is called the osmoregulatory system. Because the koi's body fluid is of a low salinity and its natural surroundings even lower or nil in terms of salinity, there is an obvious saline concentration difference. Water moves into the koi via the delicate gill lamella membrane and membrane of the gut. Also salt ions migrate out of the koi by diffusion via the gill lamella. There is a continual complex exchange of salts and fluids in order that the koi strikes a very difficult and even balance.  The koi's kidney is super-efficient and replaces lost salts by reprocessing and reabsorbing salt from urine and trace salt in the pond system. The koi is also balancing its own pH in the blood stream. The gill will exchange hydrogen and bicarbonate ions in exchange for sodium and chloride ions, in order to take up and renew lost and utilized salts from its surroundings and stop its blood pH from dropping by the accumulation of bicarbonate and hydrogen ions. This may be an explanation of why people say a high pH is not good for koi It might be the case that the koi cannot dump hydrogen and bicarbonate ions into an already saturated system with high pH. This is a very brief look at osmoregulation it will be touched on in later subjects.


As already stated the koi lives with osmosis every day, it's a natural occurrence in the day-to-day life of a koi. But there are a couple of instances when it becomes unnatural, and when this results it’s called “Osmotic Shock” and can and will result in fish death. Take an everyday koi swimming in an everyday pond none saline (typical salinity of tap water 0.05% or lower) so this could be classed as a typical, none or very low salinity pond environment. As previously mentioned the koi lives with a natural osmosis taking water on board into the blood stream and tissue extracting natural elements as it goes about its business. After the kidney has finished processing these elements, this fluid it is excreted mainly via the gill (ammonia), much as animals and humans excrete waste body fluid.

The reason for this is the koi's body fluid is 0.9% salinity or = to, 1.5 oz. per imp gallon salt.  To put it into terms easier to understand, the fresh surrounding water try’s to equalize the concentrations from low to high (external to internal) or you could say the koi's higher concentration body fluids draws the fresh water into the body to equalize the concentration. Also because the body is 0.9% saline the salt migrates out of the koi to a non-saline environment (diffusion), so the koi is continually losing body salts and exchanging fluids. This is a continual process 24 hours per day, and again an involuntary action.


However if the fish has an open wound or a deep ulcer, this provides an uncontrolled entry point for the water to ingress to accomplish the equalization process, the fish has no control over this event should it arise the koi's osmoregulation system has to try to cope.


The rapid induction of water into the koi's tissue and blood stream means that the koi's kidney has a very heavy load placed upon it, as it now has to process excess and waste fluids. Eventually the kidney's function is impaired, and the influx of water can't be coped with. Then the fish begins to bloat and swell with bulging eyes (dropsy). However if you raise the salt concentration in the environment (water), you reduce the amount of water entering the fish which unloads the kidneys.

  At a water concentration of 0.9%, the inflow of water thru the ‘hole’ is greatly reduced. You are equalizing the concentrations internal and external to the fish thus decreasing the amount of water entering the body (less osmosis taking place) giving the fish time to heal and close the portal of entry for the water (the ulcer or damage).  There is another situation in which osmosis takes place in koi which does not require an additional entry point, and that’s bacterial or viral dropsy.

When a viral or bacterial infection compromises the major organs and kidney, and either impairs the kidneys function, or shuts it down. This stops the koi from ridding itself of excess waste fluid. In the case of virus there is little that can be done, as there is no recorded and confirmed cure for virus.  But for bacterial infection however there is. The koi should be supported with either antibiotics or salt and/or roflavine hemesulphate. And salt at 1.0% .This therapeutic hypertonic dose of salt draws the excess fluid back out from the fish, whilst the antibiotic or proflavine sets to work on the infection to get the kidney functioning again if not too much damage has already been done.
With these two conditions salt is indeed the weapon of choice with whatever topical remedy works for you.

When a koi is in stress it will lose body salts.

Ordinarily this is a normal event, but because the koi is stressed its kidney will not replace salt by process from its normal sources.
From all the above it is also easy to see why salt used as a stress aid does work. As a slightly hypotonic salt solution in the pond water will greatly reduce the koi from losing salts, and stops the osmotic effect on fluid induction.

1. A salt solution equal to the koi's own saline concentration is said to be isotonic.
2. A salt solution greater than the koi's saline concentration is said to be hypertonic.
3. A salt solution less than the koi's saline concentration is said to be hypotonic.


When a filtration system breaks down and toxins are not processed as would normally be the case, or a new virgin filter is being cycled, we can normally expect to experience high ammonia or nitrite levels. This will soon have a negative effect on the koi if left unchecked. As these levels take up to 6 weeks to subside, we then have to consider other ways to help the fish deal with these toxins in order that the koi survives, and salt can go a long way to this end. A well-salted pond protects the koi in a few ways. First off when dealing with high ammonia salt helps the koi over produce mucus, and this offers protection in the short term from, ammonia irritation and ammonia burns. I say short term because ammonia normally subsides in about ten days or so. By then the nitrite is on the way up to dangerous levels and this will take the rest of the afore mentioned time span to abate.
Nitrite toxicity affects the koi by altering the hemoglobin in the koi's bloodstream, affecting its capacity to carry oxygen. If a koi hemorrhages whilst suffering the effects of nitrite toxicity it will be noticed that its blood will be brown instead of bright red (brown blood disease). Salt helps with this condition because the Chloride anion competes with the nitrite anion for entry into the gill lamella, thus alleviating some or most of the toxic effects. Plus it will also help the koi deal with the stress and fluid loss whilst dealing with this dilemma.


Upon introduction of salt into a filtered system many people say that salt does not affect the helpful bacteria in the media. This is both true and untrue to a curtain extent. A salt solution of 3.0% will destroy all filter bacteria but we do not use these concentrations in the koi pond
Salt added at 0.3% or 0.6% or 0.9% or even 1.0% although perceived to be of no effect to filtration bacteria will in fact destroy curtain types of bacteria in the filter. But equally there are types of bacteria in the filter that salt at these levels will not affect, and these will pull in the slack. As long as the salt is added slow enough. As with all things in life there is no gain without some pain.


It has been documented that constant exposure to low-level salt will dull out the color in koi by acting on the pigment cells called chromatophores found in the dermis.


Short-term treatments
Short-term treatments of salt in the koi pond should be limited to
1.      0.25 oz. per imp gallon (for stress)
2.      0.5 oz. per imp gallon   (parasite control or bacterial infections) this also causes the fish to over produce mucus and as a result some parasites get sloughed off with the excess mucus
3.      0.75 oz. per imp gallon (parasite control) (not recommended for pond treatments quarantine only)

4.      1.0oz. per imp gallon (not recommended for pond treatments quarantine only)

  For bacterial gill infection or dropsy (extra O2 always)
Always make sure the salt is well dissolved and never put the full dose in at once Divide dose into 4 equal parts and Spread it out 12 hours apart to avoid shock to the koi. Equally never drop it as quick if anything take it a little slower there is no mad rush, in fact there is a little table at the end of this paper to demonstrate just how hard it is to get out of the system once in there.


Caution here!  Dips are extremely stressful on the koi, as they mostly tend to be of a very high hypertonic concentration 3 oz. per imp gallon for 5 to 10 minutes very effective for cleansing the gill and for parasite eradication and bacterial infection. Warning! If the koi rolls over during this treatment don’t panic but return the fish to the pond immediately, where on it might still stay on its side but be assured it will in half an hour or so start swimming again with no ill effect. There are higher hypertonic doses than this but I do not recommend them although I have practiced them.



There are many do’s and don’ts with salt, and one of which is salt and potassium permanganate should not be mixed. This is not the case they are perfectly compatible, I have however read of cardiac arrest in koi when these two treatments are mixed, but have not seen or heard of a single case to relate to you here. But it must be born in mind that each of these two treatments in it’s their own right depletes oxygen, so extra care is needed.


I have many books that say that these two cannot be mixed and yet nobody gives good reason for this statement. I know many, many, people that treat with formalin and salt with no ill effect including myself so I am speaking from personal experience, as long as the salt level is below 0.3 oz. per imp gallon and extra oxygen is administered during the treatment all should be ok. As formalin is probably the best oxygen stripper there is. But your heart will be in your mouth the very first time you try it if memory serves.


It is said by many that anesthetic and salt should not be mixed some of this is also not true and  personally I use benzocaine and have on many occasion used it with salt with no effect either before during or after the anesthetic. However MS222 should not be used with salt. But the strange thing here is that MS222 is the water soluble version of benzocaine, so go figure. Oil of cloves I cannot comment on as I have only on rare occasion had to use clove oil, but some experimentation might be called for.

Basically as far as I am aware there are virtually no mixtures that cannot be achieved whilst using salt, apart from two or three exception listed here that can’t be substantiated, but you might want to tread a little careful if you should decide to try these for yourselves.


Now you may have formed the opinion that the author is very anti-salt. You would be very wrong. I just believe that there is a time and a place for almost everything and everything in its place. Its true I do not keep koi in salt permanently just because I can, and it * seems * like the appropriate thing to do. Koi were born to live in a non-saline environment and only live in saline by human intervention, but if you want to keep them happy and healthy salt is not part of the equation in the long term, short term is a very different matter.

 There are lots of occasions that salt is very appropriate and indeed is the only course of action. Just learn to recognize those moments in time when it is needed. Then go for it. All I have really tried to do here is lay out some basics and some explanation, as simply as I can so as the not so experienced and newcomer to the hobby can judge for him or herself whether or not and how salt is going to be used.  Based on a little more data than. “My mate uses it and swears by it!”
 I have tried to explained the why’s and the when’s and the why not’s, so as we can make an informed choice as to whether or not to use salt and how to. And ultimately that choice is always going to be yours not the koi’s. For those of you that can and will use salt and think it’s a piece of cake to get out of the system with a couple of partial water changes once in there.  This last section on the following pages is just for you.

Thank you for taking the time to reading this my first koi paper.

     An overview on salt, sodium chloride, by Duncan Griffiths 

Many koi keepers have accepted salt in the koi pond system as therapeutic and have used it on a day-to-day basis for many years.
Salt is known to be a strong bactericide and is used in many medical conditions both in human health care and in small and large animal vet practices.

In the koi hobby it is used as a prophylactic long-term additive to the koi's closed circuit environment.

Wednesday, October 16, 2013

We own a three thousand-gallon pond and every month we do a 10% water change. We have talked to other hobbyists and some say they do a water change and others say they do not change any of the pond water. My question is: When changing water in a pond how much and how often should it be changed, if at all?


We own a three thousand-gallon pond and every month we do a 10% water change. We have talked to other hobbyists and some say they do a water change and others say they do not change any of the pond water. My question is: When changing water in a pond how much and how often should it be changed, if at all?


Nature’s waters are abundant in biological materials, ranging from microscopic organisms too large aquatic plants and animals including fish. The presence of plants and animals in the aquatic environment means that there are also organic and inorganic byproducts being mineralize from solid organic materials from living or dead tissue. These breakdown products include humic acid, oils, waxes, assorted hydrocarbons, and fatty acids “all invisible residues that affect water quality. Although, it does not matter whether it is a lake, river, or the vast oceans, the waste generated by fish, our aquatic animals and plants do not accumulate to any significant extent the sheer volume of water of the habitat is diluting it. The pollution concentrations are also eradicated and diluted largely in cases such as rivers and natural pond waters, since freshwater is renewing it constantly through the intersection of topography, being stream-fed with freshwater, rainwater, and meltwater from ice or snow. 

However, the typical ornamental pond operates as a closed recirculation system, with the same water remaining in the pond for weeks or months at a time, even if it rains frequently this will make an insignificant difference. In this situation water quality is always a problem because as time passes various physical, chemical, and biological processes working in and around the pond alters the initial tabula rasa characteristics of the water. 

 In an enclosed ecosystem such as our ponds, a void of an overabundance of plants and ion nutrient users, most hobbyists think they can make their ponds oligotrophic in nature, but this is much harder than one thinks to achieve. Because; most of the time filtration systems are inadequate at the removal of pollutants generated by the inhabitants and clean highly oxygenated water is dependent upon the filtration systems capabilities and the amount of water that is being exchanged by the hobbyists periodically. 

 There is little argument whether a periodic partial water change is necessary to maintain a healthy pond that fish can live in without undue stress. I also think that all hobbyists would agree that all ponds would benefit from more frequent water changes and generally this would be “the more frequent the better.” However, how much water should be renewed and how often should such changes take place are often a matter of discrepancy. Finding unambiguous answers to these questions in hobbyists’ books and monthly periodicals may become a crapshoot at best. Too many hobbyists do not understand the mathematical equations used to determine whether water changes would become beneficial or redundant in an enclosed ecosystem such as our ponds. 

One thing hobbyists must understand is the idiom Pollutant Equilibrium (or PE for short). Pollutant Equilibrium means that the amount of pollutants that are being produced by the animals, plants, filter and the amount the water that is exchanged from periodic water changes will reach what is called a steady state or constant state. This means when a steady income of pollutants are being produced at a given rate and water is being exchanged at a given rate that everything will remain on an equilibrium with each other and nothing will increase or decrease over a given time. If pollutants overshadow the amount of water being exchanged then the amount of pollutants will increase over time to toxic levels even though a constant amount of water is being replaced. This arises due to inadequate filtration systems the hobbyist thought would work for their fish load. 

For example; let’s say you have a pond,  for the sake of argument will say this pond is 3000 gallons, that is producing 8-ppm (ppm = parts per million) of nitrogen (NO3) every month, this now becomes a constant. The hobbyist now wishes to reduce this nitrogen compound by doing a water change on a monthly basis. If the hobbyists were to do a 50 percent water change, this now would halve the amount of pollutants to 4-ppm (0+8)-50%= 4). However, do not forget that every month the NO3 levels will begin again to elevate another 8-ppm. In addition, you must include the NO3 compounds that were remaining from the last water change. The next month will make the pollutant level elevate to 12-ppm before a water change (4+8)-50%=6). The next month after that it will elevate to 14-ppm (6+8)-50%=7) and so on in their pond. It would now take eight months before a PE is then reached.


Then every month afterwards, the Nitrogen compounds being produced, and the amount of water being exchange would be in equilibrium with each other, and would remain at a constant 15.9-ppm NO3 levels or a steady state. As you can see the hobbyists even after conducting a 50 percent water change of 1500-gallons, may still run into problems with cyanobacteria and algae buildup, as green water in the pond. Because their nitrogen compounds have now exceeded the safety margin of keeping nitrates below the 15-ppm limit every month before a water change is executed. 

 If the same hobbyists were only to do 20% water change every month, it would take over sixteen months before a PE would be reached of 39.0-ppm NO3 levels. If the water changes were only 10%, calculation similar to those used above, would show the ensuring situation deteriorating even further, with the pollutants stabilizing at 20 times the amount generated from one water change to the next. Besides, the PE values differing with different extent of water being change the time it takes for PE to be reached also differs. In reality, doing a water change of anything less than 40 percent would be useless in anybody’s pond. The consequences of increasing or decreasing the frequency of water changes or the volume of water replaced on each occasion would only be anyone’s guess. Do to the fact the hobbyists not knowing the exact aleatory nature of the biomass and how much pollutant matter is being generated in a single day of the pond existence. 

Therefore, with the information that we now know regarding the buildup of pollutants and routine partial water changes we can conclude the following. Starting with pure unpolluted water, pollutants in the pond will progressively increase with time, even as partial water changes continue at regular intervals. However, this increased does not continue unabated but stabilize as it reaches PE. The greater the proportion and the shorter the rĂ©gime-time between each renew water change the lower the PE would be and the shorter the time it will take the PE goal to be reached. As you can see, winning the battle against pollutants in an enclosed biotope such as our ponds seems almost to be futile1. This is because the amount of nitrogenous wastes produced is many times greater than the pond’s natural capacity to absorb it.

 However, one of the biggest weapons we have in our arsenal which is in our favor is a well-designed filtration system, which we can implement in the battle against the pollutants. Now we come down to the one big problem that all hobbyists are faced with and that is “the well-designed filtration system.” Since this is easier said than done the hobbyists are left with no other alternative than to do partial water changes in their pond.  

Even with the Anoxic Filtration System, as good as it is still needs to have at least two partial water changes made each year. Generally, the greater proportion of water that is changed during the filter cleanout the lower the stabilizing pollutant level in the pond would be. Because of this filtration systems capability, the Pollutant Equilibrium levels are reached within a short time-span of weeks instead of months, without all the frustrating water changes and the cost of doing them. From what we have learned, the hobbyist that does 10 percent water changes would hardly be worth the endeavor or their valuable time.

1: The fact is that the actual ammonia, nitrite, and nitrate levels in a fully recirculating biotope such as our ponds that requires supplementary biological filtration is never zero “even if the filter design ensures 100 percent inorganic compound removal effectiveness. There is always some trace amount of these compounds in bulk water because the fish are constantly adding ammonia (fish continuously excrete ammonia through their gills, as well as through diluted urine) and other organic compounds to the water body proper. The filter can only remove ammonia and nitrites from that small portion of the pond water that is moving through it at any given time. So, even as one portion of the pond water is being cleansed of these compounds, another part is being polluted at the same time.

Please help us our pond pH is 8.9, and we do not know why. All the fish seem to be doing fine, but even a large water change will only bring it down for a short time. Then for no reason, it goes right back up again to 8.9. Can you tell us why?


Please help us our pond pH is 8.9, and we do not know why. All the fish seem to be doing fine, but even a large water change will only bring it down for a short time. Then for no reason, it goes right back up again to 8.9. Can you tell us why?



This question about high pH1 is asked more by pond hobbyists than one would like to imagine. pH is a negative-base ten logarithm of the effective hydrogen ion concentration in gram equivalents per liter. Various substances exhibit similar characteristics are how they react with others substances. A broad range of these characteristics have been divided into the two categories, acids and base, with the pH measurement is related to a ratio of the base components to acid components. 

What this means is, a substance that has one acid component for each-based component, is therefore neutral and has a pH value no greater than 7.0. Anything greater than 7.0 is considered to be less acids with more bass, otherwise known to be alkaline in nature with more dissolved calcium, magnesium and other compounds in the water; the “harder” the water the more alkaline it will become. Lime leaching out from concrete cinderblocks (which is one way to increase a falling pH in your pond) is a primary source of alkalinity; it can also increase by evaporation, which concentrates the source compounds in the water. Alkalinity2 is therefore naturally decreased over time through bacteria decomposition, which produces acid compounds that combined with and reduce the alkalinity compounds. 

You would not believe how many soi-disant experts instruct hobbyists to place cinderblocks in their ponds to lift up plants and/or to use them in building their pond filters. This also includes any blocks for paving or garden use made out of concrete. You will also find hobbyists that place flagstones or limestone around the perimeter of their ponds that also can elevate alkalinity levels after a hard rain. To test to see if your flagstones have a large quantity of calcium material in them is to place one gtt 3 (drop) of hydrochloric acid on the flagstone. If it then foams up, you now know it to have high concentrations of calcareous material imbedded in the stone.  

The reason you may need to know this information is that in our freshwater ponds, fish and plants have a difficult time in exceptionally hard water. You can use this procedure for any stones, rocks, and pebbles that you may wish to use in or near the perimeter of your pond. Consequently, any calcareous material will, for an undisclosed time, add hardness to our pond waters, but this may take years to dissipate. 

Consequently, anything that is greater than 7.0 is less acid and more base and anything less than 7.0 is more acid with less base. When acid like substances merged with base like substances, they react with each other producing some byproducts and leaving the resulting solution with a pH somewhere between the two original values. The further apart the pH of the two substances, the more energy is released in the reaction. 

 To minimize the initial pretreatment or curing of all new concrete items. Place the concrete item in a large container to adequate completely submerge it. Fill the container with water and add Muriatic acid (swimming pool acid) as required to adjust the pH to 5.0 levels. This will make the water in the container very acidic in nature. Make sure you circulate continuously and test daily, adding additional Muriatic acid to maintain the pH level until no additional acid is required. This normally takes two to three days. After the pretreatment, the curing process is complete and the concrete item is ready to be used. Properly treated concrete items will usually reach an equilibrium state where the production of compounds, which reduced the alkalinity, is matched by the components being leached out of the concrete. 

A word of warning: Only under extreme conditions should any chemical means be used to adjust the pH of a pond. Attempting to lower or raise the pH by chemical means can be particularly hazardous to all the inhabitants of the pond (especially if ammonia is present) and your biological filter is not up to handling to excessive ammonia. If your pH is reasonably stable and is somewhere between 6.5 and 8.5, not only is there no need to attempt to adjust it, but you probably will do more damage to the animals and biological filter by trying to change it. Therefore, you are better off leaving it alone.


1: pH is always written in lower case p, capital H. The “p” stands for power and the “H” is the chemical symbol of hydrogen. In equation form pH = -log (H+). The pH also affects the rate at which the nitrifying bacteria oxidize ammonia and nitrite because these bacteria have a preference pH range of 7.6 to 8.2. 

2: Alkalinity and hardness (a measure of the calcium and magnesium content) are not at all related. The confusion between the two is because of the use of the archaic European term “carbonate hardness,” mainly in discussions about reef tanks. Carbonate hardness is the same as alkalinity, neither of which is related to the amount of calcium and magnesium in the water. 

3: One drop-or exactly 0.05 milliliters. It is derived from the Latin gutta, which means, “Drop.” It is used more in the scientific and pharmaceutical circles and is an abbreviation.