Sunday, February 15, 2015

Not pond related but still informative information about building an Anoxic filtration for aquariums.

Not pond related but still informative information about building an Anoxic filtration for aquariums.

A while ago I posted something on plenums, that their use in the aquarium is an essential part of the biological filters stability. The name of the article was: Placing gravel on the bottom of your aquarium is so 1960ds.
It really doesn’t matter if you are going to set up a Dutch Planted Aquarium or if you’re going to forgo plants altogether and use artificial plants. A plenum under the gravel substrate is the only way to go for optimum biological filtration.

Click on the link below to read about an experiment conducted by university students and myself, which proves if water cannot move freely throughout the substrate then anaerobic condition will predominate.

Plenums serve two purposes, one; they can have an effect on the reduction of Nitrates NO3 by negatively charging the substrate and keeping algae at bay by Dissimulative Denitrification. Two; they prevent the dreaded anaerobic situation that begins when oxygen is deprive from aerobic bacteria and favors that of anaerobic bacteria. This in turn will start what is called Assimilatory Denitrification and only make more ammonium ions that will go back into solution once again.

Remember, a negatively charged substrate attracts positive ions like ammonium; these ions facilitate aerobic bacteria and facultative bacteria. Facultative bacteria has the ability to reduce the ammonium ion into Nitrates which it will then use its oxygen (Because it has three molecules of oxygen attached to one molecule of Nitrogen) and turn it into N2 known as Dinitrogen. This ability for the substrate to do this is because of the plenum: Which allows water to flow very slowly in and out of the substrate encompassing needed oxygenated water but never allowing it to become depleted of such.

Inside the plenum redox always stays in the high mV values and never allows oxygen to dip below .5 ppm and stay in what is called an Anoxic State. Anoxic condition only means that oxygen is at 2-.5 ppm but not void of oxygen altogether. Without the plenum the substrate even with thriving plant life will turn black from anaerobic bacteria.

There are three ways of bring oxygenated water into the substrate. One, by moving water through the medium with airlift tubes or a mechanical power source like a power head. But now you will have turned your undergravel filter into a mechanical filter too.

Two, through heating cables laid on the bottom of the aquarium this intern will cause thermal convection. The trouble with this method is it only works in the colder winter months and not in the summer months when the ambient air temperature in the home is warmer. Plus, the cables may malfunction like they have on me and overheat the aquarium.

Three, with a plenum that becomes eclectically charged inside the plenum itself and then through diffusion of ions will bring water into the substrate as needed. Plants will not do this with their root systems alone. This slow diffusion of water, oxygen and molecule interface will aid in plant root oxygenation and bacteria growth. You have a better chance of avoiding dead zones and bad microorganisms’ growth populations turning the substrate black from fermentation.

The undergravel filter I use is from TopFin at Pet Smart. The box in the photo cost about $10 USD and comes with 14 black grid panels that are easily fastened together. They also have a larger box with 24 grid panels for larger tanks.

All you have to do is snap the panels together in the size you need and place on the bottom of the aquarium. Add the substrate to within ¾-1" on top of the grids, add some Laterite evenly over the gravel, and then add the rest of your gravel. It couldn’t be any easier! So why do so many hobbyists forgo this very easy way of bringing oxygenated water into the substrate? They still keep insisting on placing the gravel right on top of the glass bottom of the aquarium, now the intersection of topography is gone…like this is the right way to do it! What is so hard to understand about this simple process?

The next photos will give you a pictorial account of how to set up an aquarium with gravel, Laterite on top of the undergravel grid panels. This will work for freshwater or salt-water aquariums. In the salt-water aquarium you forgo the Laterite.

Kevin Novak Ph.D.

Supplies needed…

UG plates are kept away from the front glass for cosmetic reasons.

Adding first layer of gravel ¾-1” deep…

Good old standby…

Add Laterite evenly over the top of the gravel…

Now add remanding gravel on top of the Laterite and you’re done. Good for aquariums but not so ponds.

Reprint of article that I posted:

Placing gravel on the bottom of your aquarium is so 1960ds.

Even though this article (below) by me was written for ponds it also pigeonholes aquariums too. If you place any gravel at the bottom of an aquarium and think it is okay to do so…think again. Times have change and science now tells us differently.

 Just substitute the word pond in this articles for aquarium and it all fits.

Some hobbyists will even go as far as making their whole pond into a huge biological filter by placing rocks, gravel, and small stones on the bottom of their ponds. The same is true for what happens with this way of filtering, as with any other type. The stones will begin to clog with smut, dead Algae, and detritus. Ammonium producing anaerobic bacteria will begin to leach ammonia ions upwards out of the substrate into solution. Algae then will use this as a food source for this is a nutrient of prime importance or it has to be converted back into nitrates by the aerobic nitrification bacteria. Nevertheless, as you can see, that the pond will be plagued with the same problems as submergence filtration systems have with clogging and producing more ammonia/ammonium. 

Now let’s use this as an example or a good analogy of how the above method of biological filtration doesn’t work like it’s supposed to. Let us say you wanted to have a natural pond, and you wanted to cutout a section of X amount of gallons from biotope in a forest preserve. You then cut out this section in this biotope and placed a liner underneath it and then had it dropped into a hole in your backyard. You would think you would have the perfect scenario! Unfortunately, you would not, because once you put the liner underneath that extracted natural ecosystem you interfered with the intersection of topography, which ground water is going constantly into and out of the water body proper at the interface of the ground and water surface. The liner has cut off the movement of water through the soil or in this situation the rocks and gravel substrate. The soil substrate/roots/water interface is of tremendous importance and is now disrupted by the ponds liner. Natural ponds constantly have water moving in an out of them on a continuous basis. This is not just from the top to bottom movement but from horizontal and vertical directions as well.   

Unlike our ponds that are closed recirculating systems, natural ponds are open systems to topography and are not plagued with the same ammonia/ammonium ion producing problems. Therefore, with all that we now know, how can one solve this filtration dilemma?  

The quest to solve, this frustrating problem started me on a systematic investigation that took over sixteen years of research. Yes, I did R&D on this Anoxic Filtration system far over 16-years before it was made publicly known. The answer is not quite as simple as one would think and a great amount of scientific research was implemented in overcoming many common problems filtration systems are plague with. Is this the Holy Grail of pond filtration? Maybe not, but it is as close to it with what is known by science today. 

As the old saying goes: “If you build a better mouse trap people will buy it!” First, biophysical rules for the Anoxic filtration are different from that of filtration systems most hobbyists use in their ponds today. In the filtration systems hobbyist use, the overall efficiency of the filter is in relation to the filters-incoming foodstuff. Nutrients flux of incoming nitrogen reacts differently to levels of nitrates in the system that is if microbial mediators are in equilibrium with each other. If excess should occur, there may be a lack of balance of useful microbial mediators. This will occur when clogging of the filter medium is present or when oxygen concentrations are high in bulk water. 

 The Anoxic Filtration filter media having more anoxic and less anaerobic volume area where more efficient facultative anaerobic bacteria exist will be able to respond extemporaneously to the nutrients flux more efficiently than conventional filters do. The fact is that when glucose is randomly added to these facultative anaerobes they have an Adenosine Triphosphate (ATP) yield of approximately 34 times that of anaerobic heterotrophs that are present in clogged filters or gravel bed filters. 

Adenosine Triphosphate s corresponds to the speed and efficiency nutrients can be reduced to make energy. Organic carbons do not limit these bacteria and mineral nutrients as heterotrophic bacteria are, which will have a negative impact on other chemolithotrophic processes. With the Anoxic Filtration System, biochemical pathways are always open and never clog. The oxic–anoxic interface microbial processing is the principal processing, controlling electrons flowing from organic matter to oxygen in molecular diffusion. This filter also has a diffusion of nutrients through it influenced by electrical charge. The filters Biocenosis-baskets are negative mV. Moreover, in the pond are many charged molecules, which most are positive mV. 

The more positive nutrients are naturally attracted to the filter Biocenosis-baskets that are then used by facultative anaerobes. These bacteria are thirty times more efficient than bacteria in oxygen free zones, make better use of phosphorus and only trace amounts of phosphates. Reducing nitrates back into gas elements, (Dinitrogen [N2] is called Dissimulative Denitrification.  

Making up Biocenosis-baskets for the Anoxic filtration and plants is really quite simple. The supplies you will need are large planting baskets (11" x 11" x 7" or 14" x 14" x 10"), kitty litter 10 (with no additives just plain baked processed clay), and Laterite that will be added to the substrate. Laterite is a highly weathered remnant of volcanic rock (weathering implies exposure to tropical temperatures, precipitation and forest derived humic acids over geologic time) but is not a fertilizer and is very rich in Iron and Manganese (iron is needed for plants to make chlorophyll). Taking an open cell plant basket and then fill it with Kitty litter make sure you leave a small impression in the center of the basket but this however is not mandatory it can be mixed up in the center of each Biocenosis basket, too. Take about one cup for smaller baskets and one and a half cups for larger baskets of Laterite and pouring it into the center of the basket then mixing the Kitty litter and the Laterite in the center of the basket. Now place only one layer of pond pebbles on top: This is to keep the Kitty litter from floating up after submerging it into the pond or being blown off during maintenance. Instead of using pond pebbles, you can substitute a black craft canvas/screen on top and wire-tie it to the basket. 

The Laterite will help the bacteria grow in its early stages; then once the bacteria become established it will be less dependent upon the iron in the Laterite for growth. Yet in the years to come it is still very important to maintain the Laterite concentration at all times so about every five to seven years you may have to add more to the Biocenosis baskets without plants and those with plants will be governed by the plants growth rate. The good thing about the Biocenosis basket is it will take years before clogging with organic matter (it may take 25 years or longer). You will use the same procedure for the planted Biocenosis baskets, but you will not use the black craft canvas on top of this basket only the pond pebbles with the addition of an aquatic plant of your choosing. 

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