5-02-2020, 17:27
9 761


Crystal clear water in an aquarium is the goal of almost every aquarist. If the aquarium is not maintained properly, the water can become turbid and the walls and decoration can become covered with algae. Dirty aquariums are one reason why many inexperienced aquarists give up their hobby. Keeping the aquarium clean not only makes it easier to enjoy watching what goes on behind the glass, but the aquarium also makes you the pride and envy of your friends.


Filtration is the main way to purify the aquarium water. Filtration can be divided into three different types - mechanical, biological and chemical - and the mechanical and chemical filtration operate inseparably from each other.

Mechanical filtration refers to the physical capture of dirt and debris. The dirt particles suspended in the water are sucked into the filter, where they are trapped by sponges, filter wool or a combination of these. The finer the sponge, the finer the particles it will trap.

Make sure that your filter is the right size and capacity for your aquarium. Determine the length and volume of the tank and select a suitable filter model, i.e. for an aquarium with a capacity of 180 litres and no less. Only then can the water be filtered effectively.

Rinse the filter material regularly under running water, as the filter sponge will become clogged with dirt and the filter performance will be reduced considerably.

Chemical filtration

Chemical filtration works by absorbing or adsorbing the finest suspended solids from the water. Carbon (charcoal filter) is by far the best known chemical filter material that is widely used to produce crystal clear aquarium water. Crushed charcoal is able to absorb odours and harmful substances dissolved in the water, making it crystal clear. The charcoal filter is available in the form of mesh bags or specially impregnated filter sponges, in various sizes to suit certain brands of water filters. The charcoal filter should be replaced at least once a month, as it becomes saturated with harmful substances and loses its efficiency.

Aquarium charcoal filter

Useful bacteria

Certain strains of bacteria may also be added to the aquarium water to help purify it. The bacteria are sold in the form of small vials of liquid. Add the correct amount of liquid to the aquarium according to the instructions, and it immediately goes to work, neutralizing waste products and cleaning the water. The effect of adding useful bacteria to the water is particularly noticeable at the start of a new aquarium, when the water is very turbid.

Useful bacteria for the aquarium


Fish have a large effect on the water quality in an aquarium. Goldfish and cichlids, for example, constantly swarm in the ground in search of food and generate a lot of turbidity. These fish require increased filtration with powerful water filters.


The food you feed the aquarium inhabitants also influences the water clarity. Coarse, protein-rich foods such as flakes, pellets, tablets, frozen bloodworms and mussels may cause suspended solids, also called fines, which reduce water quality and transparency.

Be careful not to overfeed fish, and remove all unfinished food from the bottom in good time. Only then will the water remain crystal clear.

Water changes

Maintenance and partial water changes in the aquarium are one of the best ways to achieve and maintain proper water quality. Regularly clean the filter elements of the water filter, siphon off uneaten food and waste products from the bottom, which may otherwise cause turbidity. Replacing a portion of the water each week reduces the nitrate content in the water and helps stabilize the pH-value.


A good short-term way to get crystal clear water in your aquarium is to use a flocculant. Flocculants clean the water by collecting tiny particles together to form larger particles, which can then be effectively removed by filtration.

Flocculant for the aquarium


Excessively bright and prolonged lighting of the aquarium may cause the water to bloom and turn green. Tiny single-celled algae float in the water, feeding on light and nutrients, giving the water a pea soup appearance. If a green tinge is the cause of the turbidity in the water, it is almost certainly due to light and algae, and the first thing to do is to reduce the amount of light.

Ultraviolet water purifiers give good results for combating green water. In these purifiers, the water passes through a tube in which an ultraviolet lamp is installed. The ultraviolet rays disinfect the water by destroying all the algae spores in it. Such a lamp is very effective, but relatively expensive. If you need a faster effect and at the same time cheaper, use a flocculant as recommended above.

Found an error or a dead link?

Select the problematic fragment with your mouse and press CTRL+ENTER.
In the window that appears, describe the problem and send to the Administration of the resource.


Dear visitor
No one has left a comment on this post yet! You can be the first!

Users of Гости are not allowed to comment this publication.