An aquarium is an enclosed environment , so any waste material released by the living organisms within it end up in the water and substrate. Unless they are removed at regular intervals , these waste materials are biologically transformed into toxic by-products like ammonia , nitrate and phosphate , which affect the water quality and harm the fishes’ health.

If you do not maintain the aquarium well , the poor fish and plants will be living in a sewer filled with pollutants and toxins , and their health will suffer.

Water changes involve more than just removing water from the tank and replacing it. Other factors such as the condition of the replacement water and the amount of water to remove , also come into play. These can affect the water quality , and thus the state of your aquarium’s health.

Colonies of beneficial bacteria grow on every surface in the tank. These bacteria are part of the biological filter ; allowing them to thrive will help improve the quality of the biological filtration system.

If you use gravel as a substrate , simply removing water from the tank only eliminates dissolved pollutants but does not eliminate the detritus and organic matter trapped within the gravel granules. If left alone , these waste materials will eventually decompose and pollute the water.

Using a gravel-cleaning siphon will remove these trapped waste particles ,and oxygenate the substrate as well , allowing nutrients and oxygen to reach the biological bacteria living on the gravel.

The aquarium size , the number and species of fish , and the types of aquarium accessories will determine the amount of maintenance required.

A small tank with a heavy load may need half its water changed every three days. A large tank with just a few fish may only need a small fraction of the water changed every week of fortnightly.

Ideally , more frequent and smaller volumes of water changes should be made. These avoid the problems of drastic fluctuations in water parameters , so the organisms in the aquarium need not cope with sudden changes in their environment.

On the other hand , too frequent water changes should also be avoided , as these disturb the fish and plants , and prevent beneficial bacteria from developing.

Under normal conditions , you should remove 10 to 25 percent of the total water volume. Try not to exceed 50 percent at a time. Do a complete water change only in emergencies such as a disease breakout or accidental water pollution.

Filter Media is the component used in a filtration system to clean the water. Many different types of filter media are available , and each is designed to facilitate a specific type of system. Below are the list of different types of filter media :

Synthetic Wool :

A cotton-wool like floss , synthetic wool traps tiny particles of waste. It should be placed as the last layer in your filter arrangement to “polish” the water. Because of its fine structure , it clogs very quickly and therefore is impractical for use in a primary mechanical filter or for biological colonization.

Sponge :

These traditional foam pads are inexpensive and easy to maintain. They are available in varying grades to facilitate mechanical or biological filtration. The larger grades of sponge , with bigger holes , can be used as primary mechanical medium whereas the smaller grades of sponge provide a massive surface area for bacteria to colonize. Sponges are also often used in external filters to separate different filter media. Many internal or air driven filters utilize sponges with medium-grade holes for both mechanical and biological functions.

Carbon :

This is a very absorbent material. It is only effective for a short period of time before requiring replacement. this is to prevent substances which have been absorbed by the carbon from washing back into the aquarium. Carbon should be used in specific situations such as the need to remove medication , a new aquarium set-up or water discoloration. It should be positioned as the last layer in your filter arrangement.

Ceramics Rings :

Measuring approximately half an inch long , ceramic rings primarily provide mechanical filtration. They act effectively as a sieve to trap large-particles waste and should be used in the first stage of filtration. Their irregular arrangement within the filter basket creates eddies of water which disperse in many paths , creating an even flow of water through the subsequent media layers.

Being porous , they provide some surface area for bacteria colonization after prolonged use , and are thus a useful source of ” back up ” bacteria. Since the pores are so small , rinsing waste from the rings will nor remove much of the nitrifying bacteria hidden in the tiny pores. However , the efficiency of ceramic rings pales in comparison to that of filter media like sintered glass or sponge pads , which provide a much greater amount of surface area for bacteria colonies to thrive.

Sintered Glass :

Whilst ordinary aquarium gravel can provide effective mechanical and biological filtration , its use is limited because of its relatively low surface area in comparison to the volume it occupies. Sintered glass , a gravel-like material , is a far more efficient option as it has a vast surface area that allows massive bacteria colonies to develop.

Sintered glass should be placed after the primary mechanical filtration media. This prevents the media from becoming clogged prematurely and requiring regular cleaning. Keep in mind that bacteria cultures take months to develop and ideally , they should be left alone as long as possible.