| As a newcomer to the aquarium hobby, you may | | | | outlet to be recycled again. |
| not be aware that as well as making your | | | | This type of filter is the easiest of all to install and |
| aquarium water clear, so that you can see your | | | | maintain. Before choosing an internal filter as the |
| beautiful fishes, the main task of a filter is to | | | | ONLY means of filtration, think carefully about the |
| break down the waste that fishes produce. It is | | | | size of your set up; remember water quality |
| the friendly bacteria that live in your filter media, | | | | relies heavily on filtration. |
| known as nitrifying bacteria that do this amazing | | | | External filter: |
| job. They colonize the media in your filter, and | | | | These are generally larger than internals and |
| their success is completely reliant upon it. The | | | | contain at least two mediums, therefore biological |
| higher the surface area of your media, the | | | | capacity is increased, and it is possible to add |
| greater the efficiency of the filter, and provided | | | | different mediums to carry out different tasks, |
| they have a plentiful supply of oxygen and | | | | thereby being more adaptable to individual needs. |
| nutrients, and kept free of debris, they will thrive. | | | | Although based on the same principle as the |
| There are many types of aquarium filter available, | | | | internal filter, these pressurized systems require |
| although you only need to consider the three main | | | | plumbing-in and are normally situated remote from |
| types for your basic set up. | | | | the aquarium, such as the cupboard of a purpose |
| Undergravel: | | | | built aquarium cabinet. External filters are also |
| The undergravel system consists of undergravel | | | | available in various sizes, and are relatively easy |
| plates that cover the whole of the bottom of the | | | | to maintain, although you should always keep the |
| aquarium; these plates are full of small slits that | | | | pipe connections maintained for obvious reasons. |
| allow water through them. Uplift tubes are | | | | Air Pumps: |
| inserted into the plates vertically at each end of | | | | As previously mentioned air pumps can be used in |
| the aquarium. The plates are then covered with | | | | a limited capacity to power an undergravel |
| about 2-3ins (5-8cm) of gravel, the gravel works | | | | filtration system, but by enlarge they have been |
| as the medium. | | | | superseded by powerheads. Air pumps vary in |
| The system can either be air operated, in which | | | | size and your choice would be dependent on the |
| case, an electrically operated air pump delivers air | | | | number of features you wanted run, and although |
| through a small tube, which is placed down the | | | | a cascade of bubbles rising to the surface may |
| uplift tube, as the air exits the small tube at the | | | | have a pleasing effect on the eye, the main |
| bottom of the uplift, it rises in bubbles at the | | | | reasons for aeration are rather more practical. |
| same time drawing water with it from beneath | | | | An air pumps primary function is to inject air |
| the undergravel plates, therefore the water is | | | | bubbles into the aquarium; what you are aiming |
| filtered as it passes through the gravel and | | | | for is to use a diffuser that produces extremely |
| beneath the plates and then up the tube to be | | | | tiny bubbles. If you have ever noticed bubbles |
| circulated again. | | | | rising in water you will have realized that the |
| The alternative to air operated, and much | | | | larger the bubble, the faster it rises to the |
| preferred, are powerheads. These are small | | | | surface. |
| electric water pumps that sit on top of the uplift | | | | The idea is to have the bubbles rise to the |
| tubes. The way that the water is filtered is the | | | | surface as slowly as possible; this then gives the |
| same as the air operated system, however, the | | | | natural process of absorption the best opportunity |
| powerheads can circulate a much greater volume | | | | to work. The longer the bubbles take to rise to |
| of water, and it is this extra power that is | | | | the surface the better the chance is of oxygen |
| necessary for an undergravel system to work | | | | being absorbed from them. However, that is only |
| well. They are also much quieter, and they vary in | | | | part of the process; the slowly rising bubbles are |
| size depending on the amount of water they are | | | | also able to carry waste gases, such as carbon |
| required to circulate. For a basic community | | | | dioxide expelled from your fishes, to the surface |
| aquarium this should be at least 3 times per hour. | | | | and into the atmosphere, which in turn reduces its |
| Internal filter: | | | | effect on pH. |
| These are normally smaller than their external | | | | It is important to note that the oxygen absorbed |
| counterpart, and generally contain only one filter | | | | in this way is only a tiny proportion of the |
| medium, usually a foam structure. They are | | | | requirement needed for your living aquarium. It is |
| powered by pumps similar in design to the | | | | from the surface area of your aquarium water |
| previously mentioned powerheads but usually an | | | | that the most oxygen is absorbed, this is the |
| integral part of the filter. As their name implies | | | | very reason for having an aquarium with as large |
| they operate from within the aquarium, water is | | | | a surface area as possible; this gives a greater |
| drawn into the filter compartment by the pump | | | | surface area for any given volume of water, |
| where it passes through the foam, (this is where | | | | which aids the absorption of oxygen and the |
| the nitrifying bacteria get to work), the water | | | | "gassing off" effect of the carbon dioxide. |
| then returns to the aquarium from the pump | | | | |