Intelligent Design / Natural Filtration

Subsea

Premium Member
In most things that I do, I try to keep it simple. While working on my Marine Engineering degree, I took a chemical oceanography elective at Texas Maritime Academy. I had just started up my first marine aquarium, Galveston Bay biotheme. In those days nobody did marine aquarium. It was 1971 and I had just completed 4 years active duty in the Air Force. For my substrate, I used crushed up oyster shells which I got from an agriculture feed store. It was used with chicken feed to assist with grinding up food in the gizzard. I collected my salt water on an incoming tide near the Galveston jetties. Anemones and peppermint shrimp were also collected on the jetties. More tank inhabitants were collected in the salt water marshes of Galveston Bay. These included grass shrimp and green mollies. For live rock, I found an oyster cluster with many small feather dusters and other filter feeders.

Initially, I monitored pH and attempted to inject chemical controls to keep it constant. Too much work and no fun, I left it alone to fend for itself. The tank responded well to being left alone. This was my first step in using natural filtration methods. Carbon dioxide in the athmosphere and abundent calcium carbonate in the water provide buffering and trace mineral make up. Carbon dosing was not invented by advanced hobbiest. It is a by product of carbon dioxide in the athmosphere and photosynthesis in the ocean. As I continued in the hobby, literature became available to learn more. For me, it all came together with John Tullock's book "The Natural Reef Aquarium". One important theme from the book was to establish a biotheme that was compatiable. Many hobbiest mix and match tank mates with disastrous results. However, the central theme of the book was "less technology, more biology". The average hobbiest today may think, that "old school" method was ok then but we are so much more advanced and have improved on that "old school science". As one begins to study on the science behind the biology and chemistry, you will begin to understand that nature is very efficient. An in depth talk with microbiologist about the efficiency in which nature recycles and keeps things working has lead me to appreciate natural filtration.

In this thread, I will discuss some of the methods of natural filtration including some of the science that makes it work.
 
In the oceans, the only natural nutrient export is denitrification chemistry with faculative bacteria in a low oxygen enviroment. The oxygen in the NO3 (nitrate) molecule is consumed by faculative bacteria with water and free nitrogen gas to go back to the athmosphere.
Just as carbon dioxide exchanges between the ocean and the athmosphere so does nitrogen. Free nitrogen gas in the athmosphere and dissolved nitrogen gas in the water is a nutrient input through a process called nitrogen fixation, which is accomplished mainly by cynobacteria.
When I started in this hobby, DSB and live rock were the accepted methods to perform denitrification. I used the Jaubert Plenum method with a 6" DSB of crushed coral with a 2mm-5mm diameter. This large diameter substrate extended the faculative zone deeper into the substrate with a larger population of faculative bacteria. This method was differrent from the DSB methods proposed by Ron Schmeck, PHD marine biologist. While there was some denitrification chemistry going on, nutrient recycling was its main purpose. Micro fauna and fana absorbed nutrients and reproduced. This feeds the corals and other filter feeders.

PS. Since those early days, it has been shown that nitrification and denitrification can happen in close proximity of each other. While I have one DSB in operation for 20 years, I would not set up a tank with one again.
 
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I have already mentioned faculative bacteria that perform denitrification chemistry. Nitrifying bacteria convert ammonia to nitrite then to nitrate in a two step process. Bacteria do many other things in the ocean and in our reef tanks. They feed coral and macro algae. Another more complex role of bacteria is to produce enzymes. For bacteria to grow, their food must be small enough to be absorbed through its cell membrane. When sluge and cynobacteria accumulate in our reef tanks, certain bacteria produce enzymes to break down these large organics to be absorbed by other bacteria. Dr Tim's "Waste Away" is one such product.

https://www.tlc-products.com/pdf/HOW TLC BACTERIA WORK.pdf

This link better discribes the science of using bacteria as the foundation for maintaining thriving Eco systems in our reef tanks.

PS. If you don't like the idea of buying bugs in a bottle, do what Paul B does.

http://www.reefcentral.com/forums/showthread.php?t=2591478&page=2
 
For me, it is all about nutrient recycling. Let us get back to my 20 year old set up. A 75G Jaubert Plenumn on top with a 30G Eco System mud filter with refugium on bottom.

Let us first discribe the Jaubert Plenum with more detail. At the bottom of the substrate is the Plenumn. Its function was to prevent substrate from going anarobic. Anarobic bacteria are 100 fold less efficient at processing nitrates. The most important operational consideration of this method is what happens in the top inch of the substrate. If insufficient janitors (aka CUC) allow detritus to move into lower levels of sandbed, then problems will develope. The perfect janitors, which reproduce in the sandbed, include bristle worms, Cerith Snails, micro stairs and the two pod brothers (amphipods and copepods). These janitors consume nutrients, reproduce and feed the tank. Sometimes, to better feed the tank, I would stir the top 1" of substrate.

Water flows from the display through a surface skimmer with unfiltered water entering the first section of the sump filled with bioballs. The bioballs brake up detritus and oxygenate the water. Then water enterers the largest section with <1" of mud. In reality, the miracle mud is a very fine silt which allows for a proliferation of worms, another source of nutrient recycling, which feeds the tank highly nutritious live food. Over the years, the mud filter increased in depth by a quarter of an inch that felt spongy to the touch. I have been told that miracle mud is high in iron an it is inert. I have never bought any. On top of the mud was the algae filter. The macro often provided a matrix for pods to inhabit and feed the tank. The macro could be removed for nutrient export or feed to fish for nutrient recycling. Because some macro is ediable to people there is another advantage to cultivating a macro algae refugium. I have eaten both Red Ogo and Grape Caulerpa. Both are excellent as is in a salad or a ceviche

PS. During lights out, photosynthic corals and macros consume oxygen and produce carbon dioxide. The production of carbon dioxide causes a shift in pH during lights out. A surface skimmer is the most important tool in preventing low oxygen during lights out. By removing scum from the water surface oxygen exchange is enhanced at the water surface/air interface. Most hobbiest use an opposite light cycle between display and refugium.
 
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While I think that foam fractionators are unnecessary to maintain a reef tank, they would be detrimental to a NPS tank biotheme
 
Carbon dosing was not invented by advanced hobbiest. It is a by product of carbon dioxide in the athmosphere and photosynthesis in the ocean./QUOTE]

For the record, carbon dosing has nothing to do with carbon dioxide or photosynthesis. Carbon dosing is adding ethanol or acetic acid (or sucrose) to an aquarium as an organic carbon source. You're talking about inorganic carbon here.

But I do like the natural setup.
 
Carbon dosing was not invented by advanced hobbiest. It is a by product of carbon dioxide in the athmosphere and photosynthesis in the ocean./QUOTE]

For the record, carbon dosing has nothing to do with carbon dioxide or photosynthesis. Carbon dosing is adding ethanol or acetic acid (or sucrose) to an aquarium as an organic carbon source. You're talking about inorganic carbon here.

But I do like the natural setup.


Yes, I was speaking tongue in cheek.

From another perspective, because we are a carbon based planet, nature uses carbon dioxide and photosyntises to grow things. From a reef aquarist point of view, he uses a carbon source to grow bacteria to be removed by a protein skimmer for nutrient export.
 
Elegance in Simplicty

Elegance in Simplicty

If you just want a mixed garden reef and don't want to be a slave with your time, then set up a simple lagoon tank. If you just want to enjoy the beauty of a reef tank without taking on the national debt, then select easy to care for inhabitants. How does one accomplish those two goals? First, leave the sump out of the design, it runs up the cost and it is unnecessary.

Design your system around the concept of a lagoon high nutrient reef tank. Use soft corals and mushrooms with assorted filter feeders. Use decorative macro like Red Grapes and utilitarian macro like Grape Caulerpa for nutrient export.

Use a 1" sand bed of arogonite to colonize bacteria for nitrification chemistry. The added benefit of arogonite is alkalinity buffering and trace mineral addition, automatically using the science of nature.

Be realistic with your fish population and don't over load your natural filtration system. Another just as important reason for conservative fish populations is the interaction between fish. If fish are crowded, it will often promote aggression between them.

PS. An added benefit of nutrient export of Grape Caulerpa is it being used for human consumption. It makes a great cheviche.
 
Cynobacteria is a survivor

Cynobacteria is a survivor

Why is cyno so prevelant in our reef tanks? It is unique in its position, it is a bacteria that is photosynthic. Cyno has been with us since the dawn of time. Without cynobacteria, earth would have a methane gas athmosphere. Cynobacteria is the main contributor of nitrogen as an available nutrient in our oceans. Through a process called nitrogen fixation, cyno converts free nitrogen into nitrate. Randy Holmes Farley in an article on Advanced Aquaria, discribes the process in which cynobacteria converts inorganic phosphate, calcium phosphate, into organic phosphate which it can consume. He further states that the process is optimized by a bio feed back loop. Imagine that, a smart bacteria.

With cyno able to process inorganic nutrients from the substrate, it does not rely on nutrients from the water column.
 
Macro Algae Facts

Macro Algae Facts

http://marineplantbook.com/marinebookpage10.htm

Major and minor nutrients required by marine algae are discussed by Russ Kronwetter.



https://www.reefcleaners.org/stocking-the-sump-refugium

In this link John Maloney discusses constant nutrient uptake and pulse nutrient uptake.
When nutrients are low, constant nutrient uptake (fast growers) algae may well begin to fade away and die. For those with low nutrient SPS tanks, pulse nutrients would be a good choice.
 
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I think I've heard your sermons before Pat ( :D ), but you still haven't posted your red and green grape cheviche recipe anywhere I now of. Seems like a good way to recoup some of the money I've spent on my tanks. :)
 
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