More On Energy and Sand Bed Aquariums

by Sam Gamble

The aquarium is more than a container to keep organisms in. We have changed our understanding to the point we can see the importance of paradoxical relationship between simplicity and complexity, is appearing to be a very important for balance. Life has a balance in every event from microscopic to macroscopic. We observe balance as being conducive to our way of life and the sustaining events of things or creatures we wish to preserve.

If you are trying to maintain an aquarium, you must consider the main culture you wish to preserve and then understand that countless microscopic events must happen to maintain the macro cultures. The best way to understand the system is to understand the single cell and what it needs to promote its equilibrium.

To help understand the key roles of sand filters we must focus on the open systems in nature to model our more finite marine application. The goal is a reduced nutrient environment as per the guideline for coral reef ecosystems and maximize energy conversion to sustain equilibria. In the case of our reef aquaria, we first build the environment trying to achieve a small ecosystem. To do so successfully the crucial elements must be provided in the ratios necessary for balance and fundamental growth and survival. A very critical element is light, "photons of energy". Just about everything can be linked to it.

The essential source of energy for living organisms comes from the sun. The energy arrives by units of light (photons) and is trapped by the pigment chlorophyll. Chlorophyll is present in the cells of green plants, and accumulates as chemical energy within the different foodstuffs. Without the sun, there would be no life on this planet.

There are two main classes that all cells and organisms can be grouped into. Their difference stems from the mechanism used to extract energy for their own metabolism; 1. autotrophs, 2. heterotrophs. With autotrophs (i.e. green plants) CO2 and H20 are transformed by the process of photosynthesis into the basic sugar compound glucose, from which the more complex molecules are made. Heterotrophic cells (i.e. animal cells) obtain energy from different foodstuffs (i.e. carbohydrates, fats, and proteins), that were synthesized by autotrophic organisms.

The energy held by these organic molecules is released mostly by combustion (oxidation) with O2 from its surroundings. The process is also called aerobic respiration. The release of H2O and CO2 by heterotrophic organisms completes this cycle of energy.

Must note, plant cells can also derive energy by respiration of the foodstuffs that were synthesized in their own chloroplasts. So then it is possible for both autotrophic and heterotrophic processes to occur in plant cells.

Also, there is a small and important group of bacteria that is capable of obtaining energy from inorganic molecules. The process is called chemosynthesis. As an example, Nitrobacter oxidizes nitrites to nitrates, and others transfer ferrous into ferric oxides, and some SH2 to sulfate.

Obtaining and using energy other than radiant (light) requires energy transformations locked within chemical or potential energy of foodstuffs by different covalent bonds between the atoms of a molecule. Inside the living cell this enormous amount of energy is not released suddenly as in the combustion (oxidation) in a flame. Instead it proceeds in a step wise and controlled manner, requiring and using dozens of oxidative enzymes that finally convert the fuel into CO2 and H2O, liberating energy.

Okay, so far the concept of light and energy fits everyone's basic understanding. Using the concepts of benthic ecology, we have adopted the use of energy pathways for concomitant balance. Autotrophic bacteria use light to make other compounds that can be used as chemical energy by other microbes (heterotrophs). We can go back to our beginning course NNR 101 (natural nitrate reduction as per Bob Goemans) to see that heterotrophic metabolism uses nutrients and oxygen to produce an associated anoxic environment for NO3 dissimilation. But, we're still having problems with nuisance algae and in some cases things like mysterious fish mortalities. Perhaps there is an answer if we look closer at "energy".

Nutrients in the aquarium's water are a mixture of compounds that will eventually end up somewhere in the energy cycle scheme of things, or accumulate until they do. Plants and animals (micro and macro) draw from this pool - chemical. Then interacting with and acting upon these functions is radiant energy. There is reason to believe there is more to these complex interrelationships of chemical and radiant energy than we are accustomed to thinking. In our aquarium, chemical energy is suspended in another medium of atoms containing orbiting electrons - WATER.

Radiant energy must pass through - interact with, this cluster of atoms and their electrons, and all the other compounds of atoms and electrons, that make up the nutrient pool. We've all seen yellow water in aquariums, so this is familiar. But, water does not have to be yellow to have nutrients effect the light characteristics.

Picture a water molecule. In a typical form, it's two hydrogen atoms bonded to the oxygen atom at 104 degrees angle, centering from the nucleus of the oxygen atom. Those patterns form a tetrahedron; a three sided pyramid.

But, in nature these bonds are in a constantly changing chaos. Oxygen is capable of splitting off to reform briefly as ozone. Water molecules can bond lightly with each other to form a weak lattice. Molecular energy is constantly changing. When chaotic water freezes into a snowflake, its crystalline structure is infinitely complex.

Before a living cell can use water, it must structure it, which takes energy, which a living cell needs for its biochemical reactions. Eight tetrahedrons form a stable liquid crystal known as a stella octangula. The more structured water is, the less its surface tension and the greater its ability to dissolve or suspend other compounds. But, such that it is, light still has to pass through water, undergo typical changes before pigmented cells can use it, or perform chemical transformation.

I think now you are beginning to see water in new light (pun intended), and more of the importance of water maintenance. In doing so, we are prepared to understand the role of water's structure with regard to light (photons of energy). For light to get to chlorophyll in the cells of zooxanthellae, it must pass through the chaotic environment of a soup of atoms and electrons. Many of the photons being absorbed before it reaches the destination. How much and how effectively the photons of radiant energy reach the cell depends importantly on the medium through which it has to travel.

Without getting into the lengthy debate of lighting types and bulb strengths, lets consider the characteristics of light penetrating the water of our aquarium. The photon of energy reaching the water's surface is a bundle that can be described as a spectrum. The spectrum, like a rainbow, is comprised of smaller units of specific wavelengths. In other words, the smaller units travel in a wave-like pattern. We customarily separate the distinction between different wavelengths as different colors.

We can only see part of the big bundle (spectrum) because of the adaptation of the rods and cones in our eyes to see varying amounts of wavelength energy. Plants, animals, and other organelles have also adaptive ranges of perceived radiant energy that may be greater or lesser than ours. In the aquarium this perceived function is other than sight. To begin with, energy's role starts independent of the organelle. From outside of the aquarium going into the aquarium, radiant energy first interacts with water and all that it contains (chemical and particulate, etc.).

In our aquariums the perceived spectrum of usable light ranges from the Red band - Green -- Blueviolet. Consider light (natural sun) and water (liquid crystal). If the sun's actual color is a Green light wave spectrum and that light spectrum passes the first few inches of the water, green algae (microscopic) would appear creating a "Bluegreen" refractrance. If the Green light passed further because of more clear water, "hair algae" could not exist in those light "wavelengths". Coral on the other hand would flourish. However, as the light travels through water energy is absorbed and there is a shift from Red to Green to Blue. In the process energy is absorbed and later desorbed.

Light desirable by coral would be inhibited by absorbence of broad band Red wavelengths. Light inhibited by absorbance would be characterized by; higher ORP, lower DO, and lower pH. If light were allowed for better passage of Blueviolet compared with absorbence of Red would look like; higher ORP, increased DO, and higher pH. A cleaner and less dense medium would do this.

Now, the difference between DO and pH in the above examples look a little like the difference between a nutrient laden reef tank and a healthy one, doesn't it. Go back to what was said about nutrients and their effect on light penetration through the weak liquid crystal - water. Hydrogen gases are formed at depths along with O2. When these are created coral and other organelles develop pigment for absorption and desorption of "photons". All it takes is energy, even at long wave lengths 500 nm -- 1800 nm to activate conversion. When conversion is activated, ion transfer between symbiotic plants and nutrients is achieved. The over abundance of nutrients blocks the light, stops conversion.

The other side to this coin is that blocked light and shunted conversion facilitates absorbtion and desorbtion in the red band. The greater the absorbence during he day (influenced by excess nutrients), the greater the emittance at night or desorbed energy. Iluminescence is created. Both of which produce light spectrums that create pigment tolerances demonstrated by organisms such as algae, and encompasses the entire 24 hour cycle.

With this approach we can see the importance of green spectrum conversion. For our reef aquariums we need to limit Red Band absorbtion and desorbtion with nutrient control in our sand beds. Nutrients should be considered more than just fertilizer for algae. Cycling nutrients helps to reduce the amounts of compounds shifting photon conversion. To reverse the effects of nutrients we must change the relationship of light and water. The easiest way is lowering the amount of nutrients accompanying the structure of water. The other alternative would be to change the characteristics of of water. Or both perhaps. Which comes easier?

Questions & comments,

Sam Gamble 102170.3150@compuserve.com