Back in the early days of marine fish keeping before we had any experience with corals etc, it was widely accepted that to maintain a healthy marine set-up, then a massive amount of equipment effort, and skill on the part of the keeper was required in order to keep water quality within the boundaries of what was at that time considered acceptable baring in mind our limited knowledge. such as multiple power/canister filters, regular siphoning of the under-gravel filter, and copious water changes to keep Nitrate etc at respectable levels, and to keep levels of detritus down, etc etc etc. With the advent of protein skimmers and their tremendous ability to remove waste products before the breakdown process begins, we saw a good overall rise in the standards we were able to maintain, and the gradual introduction to the hobby of a few hardy corals ensued. Over several more years there was a gradual shift in attitudes due to experimental work involving sand beds and live rock to the point we are at today, where it is the widely accepted fact, that using natural methods of waste removal is far more effective, better for our livestock, and gives better water chemistry than we believed possible at first.

Filtration is effectively the act of 'removing' or 'converting' the constantly accumulating waste materials found within our aquarium in an effort to minimise the build-up of harmful substances that would cause a gradual downhill slide in the overall health of the system and the animals we keep. Over the last several years there has been massive advances, not only in technology but also in the way we view this crucial area of reef keeping. Our understanding of the biological processes going on within the widely diverse reef environment has grown massively. To the point that we now (partially) understand the connections between mangrove and grass bed areas, lagoons and the reef itself. And that mother nature generally laughs in our faces when we try to improve on her methods, by using some disgustingly expensive mechanical contraption.

In an effort to cover this area in as much detail as possible 'whilst still keeping things in simple terms' we need to break down the subject of Filtration into its constituent parts. Each area plays an important role, which can be achieved in different ways. I'll try to clarify.

These are as follows-  (click to follow)

Biological. (completed)

Chemical. (pending)

Mechanical. (pending

Assimilation. (pending)

Each aspect requires a given amount of understanding on behalf of the aquarist. The reasons why are quite simple.  No 'one' aspect can keep our animals happy all on its own. What's required, is adequate coverage within each area. Some may be more important than others in some systems, but in all cases, these four main areas of filtration are key aspects to the long-term success of any closed marine aquarium.