Physical Filtration

From ReefPedia

Physical Filtration

Also known as Mechanical Filtration - is a filter that traps particles from water to give the aquariums a clean look such as foam blocks, pads or finely woaven socks. Mechanical Filtration is not used as much in the saltwater hobby as in the freshwater side of the hobby because when the filter traps the particles they are still in contection with water. So, then it becomes a bacteria hotspot and unbalences the aquarium because of all the bactieria converting the wastes and food in the nitrogen clcye.

Edit:

Can someone please edit this so I can understand it? Thanks

Mechanical filtration is one type of aquarium filtration that may be used alone or in conjunction with chemical and biological filtration. It works by removing suspended particles from the water column. This happens when the dirty water is pumped through a mechanical filter medium such as a layer of polyester fiber inside a cannister filter. The finer the filter medium, the clearer the water will become. In the most extreme example of mechanical filtration, reverse osmosis, most all particles including elements and compunds that are larger than the water molecule itself, are removed by a dialysis membrane.

The main disadvantage to mechanical filtration is that it requires regular maintenance. Particle accumulation on the mechanical medium while it is still submerged may foster an abnormally large population of nitrifying bacteria and lead to excessive nitrate concentration in the water. This may be counteracted through washing the filter medium and regular water changes. However, care should be taken to not become too aggressive with washing or water changes. Excessive water changes can upset the chemical equilibrium of a reef system and harm invertebrates, while cleaning the entire filter all at once can decimate the aerobic bacteria population in a young aquarium. This is especially true if your system has little or no biological filtration such as live rock/sand or bio media as is often the case in small freshwater tanks where only one overflow box type mechanical filter is used.

One should not clean or replace all the filter media on the same day. For example, replace the floss on week one and wash foam blocks on week two. Whenever possible, clean your dirty filter media by hand in a bucket of water taken from the aquarium. This will help preserve the bacteria population. When you leave some material "dirty," significant amounts of aerobic bacteria will remain inside the filter and re-colonize the cleaned and/or replaced media. You will have need to spray sponges when they become clogged and when tap water with chlorine is used bateria are killed. If proper mechanical filtration is in place, you should have no need to ever replace or clean bio balls or bio wheels, even if they appear to be "dirty." The film that may be seen on your bio balls/bio wheels is the bacteria and their associated compunds.

This author prefers to use a three stage system of mechanical filtration. Stage One is foam blocks around the outlets to all overflows to screen out the coarse materials. Stage two is a polyfiber sock at the entrance to a Berlin style sump which filters all incoming water before it passes through the sump. Stage three is a no-bypass style cannister filter with a very fine polishing cartridge. The mechanical filtration is used in conjunction with biological and chemical filtration.