Saturday, June 29, 2013

The secret of pond die-off with the lack of oxygen.

 Hear to help clarify some of the things that are said in this little article from the UK about stratification of ponds, lakes and rivers. 

If you studied chemistry in high school or college, you may have this mystery solved already.

Okay, first we have many things at play here. Like atmospheric conditions that will effect the turnover of layers in a water body as too release carbon dioxide CO2 from the bottom of a pond or lake from organic matter decay, causing a die off or for those that don’t know, it will appear to look as if a lack of oxygen in the upper layers is depleted.

  In most lakes and ponds CO2 escapes because the water is continually circulating, thanks to a process known as convection; Rain, cold weather, or even just wind blowing across the surface can cause the topmost layer of water to cool, making it denser and therefore heavier than the warmer layers below. The cool water sinks to the bottom and displacing the warmer water, -CO2-rich water- and pushing it high enough for the CO2 to come out of solution and into the atmosphere.

However, sometimes these processes are impeded and the convection processes breaks down. There is a physical limit as to how much CO2 water can absorb, and the waters mass or pressure that exist in all deep lakes and ponds can hold CO2 almost indefinitely. As the bottom layers become saturated, the CO2 eventually rises to a level where the pressure is low enough for it to start coming out of solution. At this point, any little disturbance can cause the CO2 to begin bubbling to the surface. So, when this happens you get a  “chimney” effect, triggering a chain reaction that in one massive upheaval can cause the pond or lake to disgorge CO2 that has accumulated in its bottom layer.

CO2 is odorless, colorless, and non-toxic; to a point that is. What makes it a killer in certain circumstances is the fact it’s heavier than air: If enough escapes into the air above the waters mass at once, it displaces the air or oxygen on the waters surface, making the intersection topography of air, water, surface exchange vanish.  A mixture of as little as 10% CO2 in the air can be fatal; even 5% can smother a flame… which explains why oxygen to a water body mass can easily be depleted of such and can’t easily be replenished. There are many instances of this happening throughout the world as I have explained. It is not that uncommon, as you would think.

In our ponds however, this is very unlikely because we artificially impregnate the water with air driven devises that churn our ponds water 24-hours a day, 7-days a week by the same chimney effect that I explain on top only with air bubbles, pumps and/or drains.

Now you know the secret of pond die-off with the lack of oxygen, the oxygen is still there only it can’t exchange with the surface of the water.
The water from this waterfall is coming out of an Anoxic Filter @ 12,000-gph there is noway you will not be releasing CO2.

Anoxic Filtration Book... Still free on Apple's iBook store

Anoxic Filtration – is it a bog filter? Part 2 By: Syd Mitchell of the UK

Anoxic Filtration part 2

Nitrifying bugs are everywhere 
Nitrifying bugs, (nitrogen cycle bugs), are abundant in nature.  They do not just grow and thrive in a biological filter.  In fact, they will grow everywhere in a pond environment.  In a natural pond, lake or river, they grow on every available surface.  This includes the pond bottom, rocks and plants.  In an ornamental pond they will also grow on all available surfaces, not just within the filter.  The purpose of a biological filter is to make a “bacteria friendly” environment that will concentrate the bulk of the population in one easy to manage area where the main nitrogen cycle will occur.  But that does not mean that this is the only place where ammonia is being nitrified (turned into nitrate).  Ammonia is also being nitrified throughout the whole pond.  All that is necessary for this to occur is a wet surface and a supply of ammonia, oxygen and carbonate.  Taking all the biological media out of the filtration system, therefore, will not stop the production of nitrate altogether, it will still be produced elsewhere.  It may not be immediately obvious but there are also ample opportunities for the nitrogen cycle to take place actually within the biocenosis baskets themselves.  The baskets are underwater and so, stating the obvious, all surfaces of the clay particles are wet.  The water that is just inside the baskets will also be rich in oxygen and carbonate, so we have an ideal place for nitrifying bugs to set up home and to convert ammonia to nitrate.  If nitrate is actually produced within a basket that is designed to eliminate nitrate, does this mean that these baskets are a failure?  Not in the least, as will be described later.

There are two equations that I light-heartedly refer to as; “what nitrosomonas and nitrobacter eat for lunch”.  They are included for those that may be interested.  It is not necessary for the purposes of this article to try to understand them, but they are how a bio-chemist would make sense of the nitrogen cycle. The description following the equations that explains what they mean has been simplified as far as is possible with all the nasty chemistry taken out.  You may need to read it a couple of times to understand it, or if you prefer, you may safely skip the equations and the paragraph that follows them.

What Nitrosomonas eat for lunch:-
55NH4+ + 76O2 + 109HCO3- = C5H7O2N + 54NO2- + 57H2O + 104H2CO3

What Nitrobacter eat for lunch:
400NO2- + NH4+ + 4H2CO3 + HCO3- + 195O2 = C5H7O2N + 3H2O + 400NO3-

What the equations tell us
You can either count atoms and molecules, or you can take my word for it, that these equations could very, roughly be described as saying:-  One molecule of ammonia + four molecules of oxygen + seven molecules of carbonate becomes one molecule of nitrate + a bit of bug tissue (that is what C5H7O2N means in these equations, a molecule of “bug”).  In other words, the bacteria can be thought of as “eating” ammonia, oxygen and carbonate and getting slightly bigger.  (Eventually when they have consumed enough, each bug will divide into two separate bugs, but that is beyond the scope of this article).  If we ignore the carbonate and also ignore the fact that the bugs are getting fatter in this process and we just concern ourselves with what happens to the ammonia, it gets even simpler.  One ammonia + four oxygen eventually equals one nitrate.  Let us now apply this to what is going on inside a biocenosis basket, and follow the ammonia molecules as they are drawn by the Laterite into the baskets to their doom.

See figure 1.

Figure 1.  For clarity, zones A and B have not been drawn to scale.  In practice these two zones are only a few millimetres thick before all the oxygen has been exhausted.  

Zone A
Negative charges in the Laterite start to attract ammonia molecules towards the centre of the basket.  As these molecules pass through zone A, nitrifying bacteria, (nitrogen cycle bugs), will grab one ammonia molecule and four oxygen molecules; they will then excrete one nitrate molecule.  The ammonia level in zone A will have dropped a little, the nitrate level will have risen by roughly the same amount but the oxygen will have dropped considerably, (four times as much).  Although there is now far less oxygen, there will still be enough of it for the nitrogen cycle to continue. We will continue to journey with the Ammonia molecules into zone B.

Zone B
As more and more ammonia is converted to nitrate, the ammonia level drops even more and the nitrate level rises.  So much oxygen has been used in the process that this area can no longer be called truly aerobic, (oxygen rich), but there is still a little oxygen left to sustain some nitrifying bacteria so we will follow the remaining ammonia as it journeys into zone C.

Zone C
The bio-chemistry in this zone is the stuff of nightmares and almost defies simplification, but I will try.  The ammonia is still being pulled remorselessly toward the Laterite but almost all oxygen in the water has already been used.  The nitrogen cycle, as we know it, ceases.  Nitrification cannot occur if dissolved oxygen levels are below 2 ppm, and it will be lower than that in zone C. In this zone, facultative anaerobic heterotrophic bacteria live.  The first thing to understand about this zone is; what on Earth is a facultative anaerobic heterotrophic bug anyway?  Roughly speaking, facultative anaerobic, means that it has the facility (or ability) to live anaerobically, (where there is very little oxygen), provided it can steal some.  Heterotrophic bacteria is simply a description of their “eating” habits; they like to “eat” organic molecules.  So a facultative anaerobic heterotroph is simply a bug that can live where there is very little oxygen and likes to “eat” organic molecules.  That wasn’t so hard was it?

Where it can steal its supply of oxygen from is not hard to understand either.  Remember the nitrate that was produced by the nitrogen cycle bugs?  The chemical symbol for nitrate is NO3, (one atom of nitrogen, joined to three atoms of oxygen).  For a facultative anaerobic heterotroph, this is a feast.  It can easily take the three oxygen atoms and leave the nitrogen.  Although it is convenient to refer to bugs “eating” ammonia or nitrate and needing oxygen, in practice, they do not have little mouths, nor indeed, do they have lungs.  Ammonia, nitrate and oxygen are simply absorbed directly through their cell walls, just as if we were able to eat by placing food onto our stomachs or breathe by absorbing oxygen through our chests.  When oxygen is taken from nitrate in this way, the atoms of oxygen enter the bug and the nitrogen is left behind.  This nitrogen is still dissolved in the pond water but it will be pleased to leave the water behind and go back into the atmosphere at the first opportunity.  In this way, although there are nitrogen cycle bugs living in the biocenosis baskets and they will be busy putting nitrate into the water, other bugs in that same basket are just as busy disposing of it.  The overall effect of a basket is to totally remove ammonia with no by-product chemicals remaining in the water.

There’s more
If that was all a biocenosis basket achieved, it would be pretty marvellous, but there is even more science going on.  We haven’t even considered the full extent of what the Laterite is doing yet, other than to say that “electrical charges” attract ammonia molecules toward the centre of the basket.  How does it do this, and what happens to the ammonia when it gets there?  Molecules are not little magnets, but for a basic understanding of how molecules work, it is convenient to imagine that they behave just like little magnets.  When we played with magnets as children, we discovered that two similar magnetic poles repel each other but opposite poles attract and will stick together.  Molecules behave just like that, but the forces are electrical charges, similar to static electricity, not magnetism.

The charge on an ammonia molecule (NH4+) is positive, and the charges on the Laterite are negative.  Opposite charges attract, and so ammonia molecules will be pulled inside through zones A, B and C as described above.  So, the Laterite has been responsible for attracting ammonia from the pond water flowing past the basket, right into its centre.  Although some of the ammonia will have been totally disposed of along the way, much will still remain, and once it is there, it cannot escape.  The way Ammonia is taken up by plants roots is a complex relationship involving yet more molecular charges and it is not necessary to understand this mechanism in order to understand how biocenosis baskets work.  It is sufficient to say that the Laterite attracts ammonia right up to the plant roots and holds it there.  When the plant is good and ready, (dependant on more bio-chemistry), its roots will simply absorb the ammonia and the plant will produce luxuriant growth.  Yet more ammonia has been permanently removed from the pond ecology.

What happens in unplanted baskets?  More bugs, I’m afraid.  For those biocenosis baskets that do not contain plants, the facultative anaerobic bacteria that inhabit zone C will perform a second clever trick.  Earlier, we discovered that these bacteria preferred to take oxygen directly from the pond water, but when there was little or no oxygen available, as in zone C, their first trick was to obtain some by taking the atoms of oxygen from any nitrate that had been produced by the nitrifying bacteria, (nitrosomonas and nitrobacter).  What happens when they have used up all that nitrate?  They simply switch to directly metabolising ammonia to provide their energy needs!  The expression “clever as a sack of monkeys” should be changed to “clever as a basket of bugs”.  Whether or not the biocenosis baskets contain plants, the ammonia that is drawn into a basket has no escape.  If plants don’t get it, the bugs will.

 Not every pond keeper wants to have a pond full of aquatic plants behind their Koi pond, or they may not have the space to do so.  The fact that the biocenosis baskets do not have to contain plants to mop up ammonia because a colony of bugs will soon develop and will take the opportunity of a free ammonia lunch, enables anoxic filtration to be sited indoors or disguised under decking.

Building the system

Fortunately, building an anoxic pond is far easier than understanding how it works.  In Kevin Novak’s original pump-fed design, (figure 2), water is pumped from the main pond into the anoxic pond.  In order to prevent the flow of water from disturbing the baskets, it enters through a simple diffuser.  Figure 4 shows Kevin’s suggested diffuser but any other design could be used if preferred.  The water then returns back to the main pond by gravity.  The anoxic pond should be about 24 inches (600 mm) deep and it can be any convenient shape that is large enough to allow approximately one basket per adult fish.

It is possible to modify the design to a gravity fed system for those who do not like pump fed systems or who want to modify an existing gravity fed system (see figure 3).  As in the pump fed system, the water should be diffused as it enters the anoxic pond.  One way to achieve this would be to extend the 4” bottom drain pipe above water level and to drill around 100 x ¼” (6mm) holes in it.

Are there any drawbacks?

There are no drawbacks but one point is worth careful consideration.  Settlement will occur in the anoxic pond and it will eventually need to be emptied or flushed to waste just as any other settlement chamber.  In order to keep the drawings as simple as possible, I have left out details of pre-filtration and a drain to make emptying easier.  A sieve is a suitable pre-filter for the gravity system and a simple way to close off the main pond when a gravity fed anoxic pond is being emptied would be to make the perforated section of pipe removable and have a suitable length of un-perforated 4” pipe that can replace it whilst emptying.

And the advantages?
Apart from the reduction in nitrate levels, and the fact that the system can be built so inexpensively, it is ubiquitous.  It will fit anywhere because it can be built to fit whatever space is available; the only constraint is that there should be about one basket per full size fish.  But even in this, there is flexibility.  If ever you need more baskets and space is limited, simply stack an extra layer of baskets on top of the bottom layer, taking care that they are spaced so that the bottom of one basket doesn’t rest directly on the surface of the one below so that water can still flow past all surfaces of all baskets.

The future
The anoxic system has been developed in America over the past 20 years.  It has gained considerable respect over there, from those who have tried it and found that it provides nitrate reduction even below that of the incoming tap-water, leading to crystal clear pond water.  In this country it is becoming a much talked-about subject and I believe that none who have tried it so far are disappointed.  Keep your magazine subscription up to date, there will be more written about anoxic filtration in the near future.

The anoxic filtration system was design by Dr Kevin Novak PhD.  Full details have been published in his CD book which can be obtained directly from him or read on-line at (click “anoxic filtration”).

Figure 4.  A simple diffuser to prevent water currents in the anoxic pond disturbing the baskets.


Anoxic Filtration Book... Still free on Apple's iBook store

Pre-Filters and the pros and cons about them.

 I can see there’s a lot of talk about pre-fertilization and the pros and cons about such. I will let everyone know what scientist already know, that I, assumed everyone knew already. However, some hobbyist may start getting confused over the discussion that is going on here on KoiVet.

 First, a pre-filter is nothing more than a mechanical filtration system/device. It is not and was never intended to be a biological filtration system nor should any hobbyist assume it is. Whatever pre-fertilization one uses before biological filtration takes place, is strictly up to the hobbyist and their priorities on maintenance.

 Second, the cleaner the pre-filter stays, the higher the redox of ones pond will be and the longer before cleaning intervals of the biological filtration.

Last, but not least, all pre-filters should be easy to maintain, the easier it is to maintain the device, the more readily a person is likely to keep up with its maintenance.

For example; my pre-filter is nothing more than a large drainage box that you can buy at any hardware store.  It draws water from the main pond bulk water from its top, with an 3624gph hobbyist pump; through several filter mediums before water is dispersed by a diffusion system into the Anoxic filter. About 90% of all particulate matter is now withdrawn from its incoming source before it becomes diffused in the filter. I myself do not know what the big fuss is about pre-filtering the pond water before biological filtration takes place.

Even with such a simple device, what we notice through testing (this was with all ponds using a pre-filter before biological filtration) is that the longer the intervals between cleanings, the lower the redox became and the turbidity of the main pond suffered. Through this did not show any immediate affect on the animals’ heath per-say, we did notice that the metabolic rate of the animals increased. After cleaning out the pre-filter, within twelve hours the fish were back to normal. Though these studies are not conclusive, it does bring up the question of how water quality deterioration can affect our animals very quickly, without one noticing this deterioration by sight alone.

We also notice that the dirtier the biological filtration system became, this also correlated with what we found with dirty pre-filters, redox always suffered. Bottom drains that were not pre-filtered before biological filtration takes place were always an issue that drew much attention on the bulk water parameters and how well ones animals did in the long run. These insults sometimes will overwhelm the biological filtrations bacteria’s ability to process foodstuff. If any hobbyist pumps the bulk water from their pond in any manner, without per-filtering that water first, redox will always suffer and biological processes will be influence by such macro and micro particulate matter. Such insults are to be avoided at all cost if one can help it. In order to overcome these problems, filtration manufacturers are always trying to make filtration systems that will carry more biological surface area than ever before. I think the word I should be using here is “clogging” by particulate matter and not only by bio-film.

 The last time I cleaned my filtration system out, was in late winter (March) and I told one of the KoiVet administrators, that he could look at my filter himself to see how dirty it was if he liked. After five months of running with a heavy fish load, and feedings, the filter still looks clean (it is not a big settlement chamber full of detritus as some hobbyist think), with very little detritus and smuts. In other words foresight is far better than hindsight in planning a good filtration system and pre-filter.

 My fish and my beta test pond fish are not as old as they are for no good reason (25-years for mine and 20-years for his, true age). They are as old as they are because we allowed water parameter to stay as high as we humanly possible could with reasonable expenditure on our part, to keep it that way. I must admit that the work expenditure is minimal, at least I think so. However, we also failed in are husbandry like all people do, and let things laps for too long a period, and the only thing that carried us through those lazy times; was the Anoxic filtration system.
 I guess spending a few minutes a day cleaning out a pre-filter is a mall price to pay, than replacing a $2000.00 dollar Koi, or going on KoiVet looking for a cure for an exacerbating problem that’s making our fish sick. However, that decision is up to each individual, and how much work they wish or willing to expend on their ponds.

For me, I clean my pre-filter out once a week and if I am in a good frame of mind, maybe twice a week, but that is only if I am in a good mood. However, any pre-filters cleaning, will be dictated by the parameters of the pond.
I also will add, even though I advocate at lest two large water changes when cleaning the Anoxic filtration system each year, and this is “bare minimum” on water changes. Some hobbyist will not even do that, because it is too much work or their water bill will get too high. As I said before, people are going to do whatever they want, and not always, what we tell them to do, a good filtration systems designer must consider that.
Here is a more sophisticated pre-filter use in Italy by Dr. Franco.
A good pre-filter is like a respirator that protects our lungs, you may get by without one, but then the risk you take could be fatal if neglected.

A newly set up pond using an Anoxic Filter first being pre-filter before any water goes to the filter itself.

Anoxic Filtration Book... Still free on Apple's iBook store

Anoxic Filtration – is it a bog filter? Part 1 By: Syd Mitchell of the UK

Anoxic Filtration – is it a bog filter?

Part 1    By: Syd Mitchell of the UK

Take a planting basket, fill it with cat litter, then scoop out a depression from the centre and fill that depression with an aquarium plant fertiliser called Laterite.  Put a plant into the basket if you wish, but it is not necessary. 

If it is that simple and inexpensive to make a Biocenosis Basket, why are more Koi keepers not using the anoxic filtration system?  Possibly the answer lies in the fact that it is rare to find a Koi keeper who actually understands what anoxic filtration actually is, what it does and how it works.  The reason for this lack of understanding should immediately be obvious.  Already, I have used three words that many Koi keepers will find new and mysterious.  What is Laterite?  What is a biocenosis basket?  And isn’t anoxic, something to do with anaerobic sludge where harmful bacteria can live? 

If it were possible to describe the anoxic system without using such words I would do so, but, whilst it is easy to build the system, the way it works is extremely complicated.  So let us begin by explaining what Laterite, biocenosis and anoxic mean. 

Laterite: - This is easy enough to understand.  It is simply a clay based material that is rich in iron.  It is used in tropical fish tanks as a plant fertiliser and can be brought from tropical fish dealers.
Biocenosis: - This is a scientific term for a place where different biological processes take place, each process being of mutual benefit to the other processes. 

Anoxic: - Anoxic does not mean the same as anaerobic.  In an anaerobic region there is a complete absence of oxygen.  In an anoxic situation, there is oxygen present but it is at a very low level.  In a biocenosis basket there is always a low level of oxygen.  Levels are typically between 0.5 ppm (mg/L) and 2 ppm. This is the key factor that will influence a situation where anoxic filtration can occur.  The presence of an extremely low level of oxygen is crucial to the system as will be described later.  In passing, it might be worthwhile to contrast the oxygen level in a biocenosis basket with the oxygen level in the pond itself.  The absolute minimum acceptable oxygen level in a Koi pond is 6 ppm, although 7 ppm is more often recommended as a safer minimum to adopt and, in practice, it should be at saturation level (as high as is possible at any given temperature). 

With the first few terms explained, it should now be possible to move on to a better understanding of how the anoxic filter system is quite unlike any filter system that is commonly in use by pond keepers.  There will be more complicated terms as the description unfolds, but each will be explained as we explore the system.  To contrast anoxic filtration with conventional filtration, it is first necessary to understand how biological filters actually work. 

Conventional biological filtration

Fish continuously excrete ammonia which is toxic to fish, and so it has to be removed from the pond water before it can cause them harm.  We all know this.  Any well designed conventional biological filter system will be effective at taking this ammonia and converting it, first into nitrite, and then into nitrate by a process called the “nitrogen cycle”.  This is also well known.  Having achieved the conversion of ammonia into nitrate, the task of a conventional biological filter is complete.  No further biological action to remove the nitrate takes place and so the level of nitrate in the water slowly rises.  This is the first disadvantage of conventional bio-filter systems.  Nitrate is nowhere near as toxic to Koi as either ammonia or nitrite but that doesn’t mean that they are not affected by it.  Hard scientific research on this subject is difficult to come by, but, there is plenty of anecdotal evidence to show that Koi kept in low nitrate ponds, show better growth and colour development than those kept in a pond where the nitrate level has been allowed to rise.  Easier to prove, is the effect that nitrate has on algae of all types.  Nitrate is a plant fertiliser.  A rising level will encourage blanket weed and the kind of algae that turns water green.  Water changes will help but, even after a 10% water change, the nitrate level will still be 90% of the original value, and, as more ammonia is converted, the nitrate level will soon begin rising again. 

There is a second problem with some conventional biological systems, which is that the biological media can become anaerobic (no oxygen at all).  This will not occur with moving media such as fluidised sand or aerated K1, but where the media is static, water flowing through it carries suspended particulate matter as it passes through.  This will settle within the media, and, over time, can cause it to block.  Water will not easily be able to pass through blocked areas and will tend to bypass them.  The water will find it easier to flow through areas that are not blocked (yet!).  Water flowing through media carries oxygen to the bacteria that are living within it.  As the flow through a particular area reduces, the bacteria in it will find that there is less and less oxygen in their environment.  The bacteria that have been oxidising ammonia, firstly to nitrite and then to nitrate, will have been using a great deal of oxygen to do this.  As the media becomes clogged, they will find that they no longer have the oxygen available to carry on this process.  There are bacteria that need oxygen as part of their biochemistry, but, in some ways, can be thought of as being far more clever than we are. If we are deprived of oxygen, we soon die.  These bacteria normally take the oxygen that they need directly from the water surrounding them, but if there is no oxygen in that water, there is a way they can get it.  They can take oxygen from nitrate.  Nitrate (NO3) is the end product of the nitrogen cycle, (as far as Koi keepers are concerned).  It consists of one atom of nitrogen joined to three atoms of oxygen.  These bugs can take away the atoms of oxygen from nitrate.  In doing so, they reverse the nitrogen cycle. 

Our two favourite nitrogen cycle bugs, nitrosomonas and nitrobacter, will be as busy as ever converting ammonia to nitrate in the aerobic areas of the biological filter, but bugs that can live in anaerobic conditions will rapidly colonise the anaerobic areas and will become equally busy taking the oxygen that they need from the nitrate that has just been produced by their cousins.  This will result in that nitrate being converted back to ammonia again before it leaves.   This is a completely pointless exercise, yet it is exactly what is happening in many filter systems where the biological media is not clean.  At least part of the good work being done by the bugs in the oxygen-rich areas, is being undone by bugs in areas that are deprived of oxygen. 

The anoxic filtration system was designed and has been developed over many years by Dr Kevin Novak Ph.D. and it addresses both these problems. The anoxic system does not rely on converting ammonia to nitrite and then into nitrate.  With the anoxic system, ammonia is either converted directly to nitrogen gas, (more correctly called di-nitrogen), by bacterial action in the unplanted baskets, or it is taken up by plant roots in baskets that also contain plants.  It is well known that plants “like” to feed on nitrate.  What is less well known is that plants actually “prefer” ammonia as a food source, and will take it directly from pond water if it can be presented to their roots in the correct way.  The process that causes this to happen will be described in detail in part 2 of this article, but for now, please just accept that ammonia molecules are attracted into the baskets by the Laterite that we put into the centre.  

Another important feature to understand is that it is only the ammonia molecules that are drawn into the biocenosis baskets.  Obviously, water floods into them when they are immersed, but after that, water does not actually need to flow through them in order to filter out ammonia.  The Laterite in the centre of the basket only draws in ammonia molecules; it doesn’t draw in water molecules.  This directly addresses the second possible problem that can happen with some of the static types of conventional filter media I mentioned earlier – that suspended particulates can clog media and it will then become anaerobic. 

Critics that have not taken the trouble to understand how the anoxic system works, often wrongly describe it as a “bog filter, full of nasty anaerobic bacteria”.  They warn that the baskets are a breeding ground for parasitic bugs that can then spread to your fish.  In fact the direct opposite is true.  Biocenosis baskets cannot clog because, if no water flows through them, there is no way that debris can be carried inside.  On the other hand, if water flowing through conventional media does not have every speck of debris filtered out of it, there will always be the risk that sludge will settle inside and block the media.  So, far from a biocenosis basket being a “bog filter”, it is more likely that this label could be applied to a conventional system that has not been kept sufficiently clean! 

The anoxic filtration system

Figure 1 shows a typical anoxic filtration pond without the plants.   It is simply a shallow pond, around 24 inches deep, with water being pumped into one end and overflowing by gravity back into the main pond at the other.  This one contains 22 biocenosis baskets.  The small pebbles on top of the baskets prevent water flowing past them from disturbing the cat litter inside and causing it to float away.  Figure 2 shows how the entire anoxic filtration system can be “hidden in plain sight”.  The anoxic pond looks like a water garden, not a filter, and yet everything except the pump in the main pond can be clearly seen.  For those who do not like pump fed systems, the anoxic pond can be gravity-fed from a bottom drain.  Build the anoxic pond at the same level as a conventional gravity fed system and use a submersible pump or external dry mounted pump to pump water from the anoxic pond back into the main pond.  The only limit to how this system can be built or adapted is your ingenuity! 

There are few hard and fast rules as to how to make biocenosis baskets.  It is important that the planting baskets used should have open lattice type sides to allow ammonia to be drawn in through them, but apart from that, any basket around 30 cm x 30 cm x 20 cm deep will do. The cat litter should be a granular, unscented, “non-clumping” type that should retain its granular structure when wet.  Laterite can be obtained from tropical fish outlets or purchased on-line in 1.6 kg packets for less than (GB) £25.  Biocenosis baskets need very little maintenance because the life of the cat litter is indefinite and the Laterite is only very slowly depleted by plants.  Photosynthesis is the process that plants use to make energy from sunlight and a green pigment called chlorophyll is essential for this process.  Plants need iron to make chlorophyll, so if there is a plant in the biocenosis basket, the iron in the Laterite will become exhausted after about five to ten years and you will have to add some more Laterite or remake the basket. 

Part 2 will describe how to build the anoxic filtration system, and how ammonia can be drawn into a basket and destroyed without leaving nitrate to build up in the pond.

Photo #1  Old milk crates to diffuse the water.

Photo #2   This pond also has an electric fence to keep the Raccoons out.


Anoxic Filtration Book... Still free on Apple's iBook store

Friday, June 28, 2013

Education is the key in achieving ones goals in life... also, A story about Dr. Bob and Anne Passovoy's pond.

Education is the key in achieving ones goals in life.

 In 2007 the name sayers were out in full force on the Anoxic Filtration System, today they have been proven very wrong.

One of the NI members thinks that 99% of all the NI members would not be interested in my cd-book and would find the information therein to be unsuitable for Koi hobbyist. He himself definitely would not be interested in my cd-book in the slightest. He could not be further from the truth if he tried. In this apologia, I will try an assuage what he has said to all readers of NI.

By the e-mails, I have been receiving and with the now over one hundred seventy-five cd-books that I have given out, in over five continents, I would say the NI-world is not in complete agreement with his conjecturers. In no part in my responds to Mr. James P. did I ever mention nor did I imply that my cd-book was not for Koi hobbyist. He has misconstrued and conjured up false percentage numbers to facilitate the needs of only a few rarefied Koi keepers in the NI forum and is not representing the NI public as a whole.

 It is undeniable that people are thirsty for knowledge and are willing to ask for it if the opportunity knocks at their door. If Mr. Chandler finds that too hard to believe, then I feel sorry for him, and I wish him all the luck in the world on his endeavors in Koi keeping. Misconstruing the definition of the words “mom and pop ponds” is really a misnomer on his part. All of us that have a backyard pond for recreational purposes fall into this category. Since most of the ponds are built on joint ownership properties, they fall into this category, at lest here in the U.S. that is. Our ponds are not considered public domain and are therefore classified private in ownership, hence the name, mom, and pop ponds. I hope this is now clear to everyone when I use the term mom and pop ponds. This does not mean water gardeners only but includes everyone that owns a pond, whether professionally made or otherwise.

The filtration system that I have designed was specifically targeted for Koi and only for Koi use. Yet, with all the studies and experiments that were taken on this system, it was found that it would really benefit all hobbyists and not just a specific class or group of hobbyist. With the feedback that I received from everyone from water gardeners to the most ne plus ultra Koi keepers. It became apparent that this system would benefit all hobbyists, whether in part or in full.
Bob and Anne's pond that incorporated some Biocenosis Baskets and found that redox went up by doing so.

I will give you one example that is now openly known, and can be validated on the Internet if one wishes. There are others, but they wish to have their privacy respected and not molested by others. Some will also be on the MPKS pond tour in July of this year.

I am a member of the Midwest Pond and Koi Society (, for the past fifteen years now, and have known this gentleman for as long. He is the president of our club and has been so for many years now. He is what I call a ne plus ultra Koi keeper, and will do anything to keep his animals in top-notch shape. Bob and his wife Anne strive for perfection in Koi skin refulgence, body shape, and color. His animals have won many trophies to boot. Whenever people come over to see his Koi, he hands out drool-buckets as to keep spittle from polluting his pond water. I think we all get the picture here don’t we? He has what most/all would call a hi-end filtration system (only a few members fit into this upper class of Koi keeping), and meticulously works on his maintenance without fail. He is an extremely dedicated and well-respected Koi hobbyist, and is never relaxed about his duties and obligations to his animals. As Bob always says, “you can never have too much filtration” I mean this guy even has a “flux-capacitor” on his pond, no kidding.

As a hobbyist, one would not think that his water quality could get any better even if he replaced a 100% of his water on a daily basis. However, his wife Anne did something that did just that, she did something that increased his redox and pushed the envelope of Koi keeping that much closer to the Holy Grail of pond keeping.

After listening to one of my seminars at the Eastern Iowa Pond Society’s Trade Show. She also took one of my cd-books and read it. She decided to implement some biocenosis-clarification-baskets with plants in them into their pond last year. So she wrote about it in one of the newsletters for this year, and I will quote: “One week later there was a remarkable difference in the clarity of the water. Like glass, clear to the bottom of the pond and the marsh garden.”
“Over the summer the lilies bloomed well without fertilizer. We had no algae problems at all. The clarity did not diminish at the end of the season, even though one or two plants had to be repotted due to Koi digging up the rhizomes when I was too slow with the lettuce. Koi health was excellent all year, and growth rates seemed to be better…”

This is just one of many hobbyists that read my cd-book and came away with a little more than what they began with. A mind is a terrible thing to waste, wouldn’t you say Mr. Chandler?

Well Mr. Chandler, still think 99% of the people of NI think the same way you do, I don’t think so. I think you’re trying to read more into what I said to James than what was really there. Your trying to make fun of people that do not have the money for a hi-end filtration system like some hobbyists can afford.

Yes and I am sure you will say that Bob and Anne’s pond really is not up to par with the best of them and you’ll go on and on trying to prove some moot point. But then again you really wouldn’t know how well or bad their pond is, and you would be second-guessing at best, and you would be wrong at that, too.
Some more photos of bob and Anne's pond.
Biocenosis Basket in the background.

Now you can view the baskets a little clearer in this photo.

Anoxic Filtration Book... Still free on Apple's iBook store