Diatoms: Saltwater Aquairum Enthusiasts Take Note

What the heck is a diatom? I am sure that many of you are wondering that same question. It isn't like diatom is a household name along similar lines of Caulerpa algae or zooxanthellae, but its gaining notoriety and should become a household word for anyone involved in the saltwater hobby, while maintaining an aquarium. Diatoms make up the phylum bacillariophyta and consist of over 5,600 living species representing some 200 genera that are either planktonic, unicellular or colonial(algae) in nature. Diatoms have been traced back as far as the early Jurassic Period of time so eliminating these organisms is not going to happen. Amongst scientists, diatoms are labeled as "jewels of the sea", due to their beautiful design and symmetry. Now, for us conscientious aquarists, the fact that these creatures are beautiful and asymmetrical with a split between both sides doesn't amount to much in our aquariums. They do have their place in our aquariums for another reason that benefits both us and our livestock.

Diatoms are mainly unicellular organisms that are also autotrophic, however, heterotrophic and symbiotic species do exist in particular habitats. Characterized by their hard shell consisting of silica(hydrated silicon dioxide) that is secreted by diatoms for protection, their identification is pretty simple to pinpoint. The shell of diatoms contains small porous holes allowing the organisms to make contact with its ambient environment. Unlike microalgae, macroalgae and cyanobacteria that can simply be removed by rubbing your fingers or sponge across it, performing this tactic will not work so well with diatoms. Taking this one step further, coralline algae is similar to diatoms as its is also a hardened algae but is formed by a calcareous carbonate skeleton. The unique difference in differentiating these two is the fact that coralline algae is red, pink, purple and green in color, whereas diatoms take on a golden yellow or brownish color. Diatoms contain chlorophyll a and c hence their photosynthetic properties and reliance on light. These unique, intricate, beautifully detailed organisms contain bilaterally or radially symmetrically paired halves.

Asexual reproduction is carried out through cell division by diatoms as a means of carrying on the species. They lack mobility as a result of not containing a flagella for the most part. Diatoms can be encountered in fresh and saltwater as well as in soils or any other local that remains damp. Most live their lives in the pelagic regions of water though their are some species that take up residence in benthic areas as well, where the substrate meets the water line.

Now, as for our aquarium environments and the importance, or lack thereof, that diatoms portray. Diatoms can add unsightly blemishes on aquarium glass and equipment if the right water parameters and lighting are favorable for their existence. They also represent a favorable and important food source for livestock in our aquariums. In fact, diatoms in our oceans represent roughly 45% of oceanic total production as a pertinent food staple for a myriad of marine life! Once light and nutrient conditions in an aquatic environment become favorable, aquarists will experience a bloom and bust scenario. As a result of this, we need to try and maintain a fine line between an over abundance of diatoms or none at all. This affords our livestock population a nice alternative and diverse microcosm of food stuff to enhance the nutritive requirements and long term success and health of our tank mates.

Most aquarists will encounter a diatom bloom initially as their tanks go through the cycling process or recently finished it. I have heard many aquarists complain about this and wondering what to do and what it is that is ultimately overtaking their tank. Yes, cyanobacteria and nuisance microalgae also plays out negatively by those starting up a marine or freshwater tank, as the nutrients, lighting and bacteria equilibrium remains out of whack. Water changes, addition of carbon and the build up of bacteria essential for the breakdown of ammonium to nitrites, nitrites to nitrates and further removed from our tanks by various methods will ensure that these widespread and potentially hazardous results are not obtained. The major variable in determining the amount of diatoms present in an aquarium, is silicates(silicon). Test kits are available to test for this and should be considered, especially initially in the infancy stage of a tank's set-up.

Pods, algae and diatoms encountered in a marine aquarium environment, combined with food sources provided by aquarists, are proven to offer a beneficial and balanced source of vitamins, amino acids, traces and other nutrients enabling livestock to thrive in a captive environment.