Microbial
Processes
(March 2002 page 14)
Bob Goemans, BAS

When I look back in time I see most people who want to set up a new aquarium first thinking about what colorful fishes or invertebrates will be housed in their 'slice of the ocean.' Most believe a trickle filter, undergravel filter, or fluidbed filter is all they need to take care of what is termed 'filtration.'

As good as these forms of equipment are, they lack the ability to foster a system where microbial processes are performing in a balanced state, i.e., where nutrients entering the system are efficiently used and do not tend to accumulate. However, I see filtration in the context of what protein skimmers and activated carbon provide. They remove elements and compounds from the water. On the other hand, bacteria use 'metabolism' to accomplish environmental changes by transforming elements and compounds into something different. Without a doubt various microbial processes are the foundation of every aquarium system. Healthy longevity of which is based upon how well they (bacteria) function. How well they function is in turn dependent upon your knowledge of their existence and their requirements. You could say they are the heart and soul of the system.

Even though the Berlin method was a great step forward with its emphasis on live rock it could experience unwanted algae problems unless additional equipment was brought into play. Actually, the underlying causes such as microbial balance were not fully understood until Sam Gamble and I began research on sandbed processes both in the wild and closed system in the early 90's. Since then we have well over six years of in-depth research into microbial processes in all different types of sandbeds along with other associated problem areas. We have even taken our data to a biochemist and had it reviewed for accuracy. So what you are about to read is fact, not fiction.


Remember what was said in the opening paragraph of this booklet (what you are reading is a small portion of a new booklet) - 'An area of major difficulty with setting up the natural aquarium is the tendency to confuse the result desired with the techniques that may be required to accomplish it!' That simply says the wagon is often placed in front of the horse instead of the other way around. Even though many aquarists are more informed these days, there's still the tendency to think the 'nitrification cycle' is all that's required in ridding the aquarium of its toxic compounds.

As important as it is, there's much more to microbial processes as past research has shown. If attention is only paid to converting ammonia to nitrate, such as what is accomplished via the nitrification cycle, a closed system often tends to accumulate nitrate. Even though fish health is mostly not impacted, invertebrates are more sensitive. It wasn't until the reef portion of the hobby blossomed in the mid 80's that more attention was paid to nitrate accumulation. The Berlin method used live rock as a more natural way to reduce nitrate accumulation.

Yet, it wasn't until the Jaubert plenum method came upon the scene in the early 90's that another step was taken in naturally controlling nitrate/nitrogen accumulation. The method underwent intense research into its microbial processes because a 75 gallon reef test system I set up and wrote about brought the attention of Sam Gamble, Aquarium Biologist at the John Pennekamp Coral Reef State Park in Key Largo, Florida. This system rarely ever had any nitrate accumulation for five years and was only disassembled so as to move its animals to a larger system because they had outgrown the tank. During the research it became evident there was much more to understand than just the nitrification process!

Research went into all type of sandbeds, whether they were in the wild or closed systems. Different depth beds consisting of different grain size material was explored. The findings were reviewed by a biochemist and numerous articles appeared so as to bring forth what was learned. That caused some controversy, which was to be expected when a different mindset was presented. Most people welcomed the new findings, in turn applied it, and experienced very successful systems. Some misapplied the data and experienced problems with their systems, which is also understandable, at least to us but not to them. They or others hearing of their failures wrote articles base on the skewed results and announced the method a failure. How sad! It should be noted that I receive about twenty-five emails a day, some of which ask for help with failing Berlin systems. Yet, how many articles have you seen that note 'Berlin' failures? Yet they do occur!

This is not to say the Berlin method is not a workable method, but I see it as a steppingstone in the field of aquarium husbandry/progress. We learned from it, took its strong points, added new findings and developed a new method that brings us closer to the dream of successfully duplicating nature in a closed system.

One of the 'many' things learned in our research was that more focus needed to be applied to overall system 'balance.' When one thinks of "balance" a mental picture of an equal amount of something on either side of a dividing line comes to mind. Lately, the words "microbial balance" are being tied to biodiversity. The thought there is the closed system's environment needs to be in sync with what is found in the wild. Actually aquarium microbial balance has nothing to do equal sums or the vast diversity of organisms found in the wild. To be truly successful with closed systems, whether freshwater or marine, the microbial foundation of a closed system needs to contain the correct "portions/volumes" of microbial processes that adequately use the incoming energy/nutrients so accumulation does not happen.

Now think about that for a moment. What goes into the system in the way of energy, which includes food, water and light should result in the total utilization of that energy so no leftovers from all the various processes tend to accumulate in the bulk water or substrate. In other words, what goes in is properly used up to maintain the system's environment. When that happens, true balance is achieved. In all honesty that is easier to say than achieve. But, there's no good reason not to consider and understand all the revenant facts and how working towards this goal brings about greatly improved chances of a more healthy system with far less chances of unwanted algae.

One of the mistakes in our past, and I'm saying that collectively, was that we saw the aquarium as one world with everything interconnected, e.g., animals, water, light, substrate, etc. In my opinion, there are two distinctly different worlds - one being the bulk water world and the other the substrate world. Yes, what goes on in each has an affect on the other, however, what goes on in the substrate world can easily be the governing parameter. I can change water, improve lighting, but changing substrate is not feasible. For all practicable purposes bacteria don't live in water, they live on substrate of one kind or another. The two most important are sand and rock. What they accomplish or don't accomplish affects the water world.