Under natural conditions, water can self-clean thanks to natural filters. In the same aquarium, water cannot independently guarantee a sufficiently clean habitat for fish, as it is an artificial reservoir.
Then aquarists resort to biological water filtration.
Biofiltration is aimed at converting ammonia, harmful to living creatures, released as a result of decomposition of under-fed food and other fish waste in water into nitrites.
The principle of biofilters in the aquarium
It is worth considering that the bacteria themselves are a biofilter. They are involved in the transformation of ammonia into nitrates. The fillers themselves in the filters for purifying the water in the aquarium are useless until the bacteria settle in them.
Without bacteria colonies, Fish Tank Filters perform only mechanical functions, collecting fine dirt in water.
There are two types of microorganisms that are useful for the aquatic system:
- Nitrifying bacteria. Ammonia is oxidized to hydroxylamine, and then to nitrite and nitrate;
- Nitrobacteria. They feed on nitrites and process them into nitrates, which are less harmful for fish.
Beneficial bacteria are not a substance that can be collected and poured into an aquarium or filter; they already exist on the walls of the aquarium and its other elements. Bacteria multiply quickly, your task is simply to provide them with a comfortable habitat and create favorable conditions for food.
For this, biological filters are used, where the fillers are put, intended to increase the contact surface and ensure the reproduction of bacteria.
The best bacteria multiply in such fillers biofilters:
All these fillers perfectly retain small particles, contribute to the rapid spread of bacteria through the filter material and their reproduction due to the continuous flow of water in the aquarium.
Simply put, the principle of operation of all biofilters is based on the creation of favorable conditions for the reproduction of beneficial bacteria that break down ammonia.
It is necessary to ensure a constant flow of water through the filter so that the bacteria continue to multiply and cleaned the water.
For small aquariums often used biofilter bottle, which consists of:
- Tubes for spraying water;
- Compressor to supply air to the spray;
- Filter filler.
This biofilter works as follows:
- The bottle is immersed in water;
- Ammonia-rich water flows from the aquarium to the fill through the holes in the bottle;
- In a filler, for example, zeolite, a small colony of bacteria is collected, which oxidizes ammonia to nitrate, gradually multiplying and increasing the efficiency of water purification;
- After that, the purified water becomes lighter by means of a nebulizer inserted into the bottle, which creates a mixture of water with oxygen, and rises upwards, getting from the filter back to the aquarium.
How to make a biofilter for the aquarium with your own hands
It is not necessary to spend money on the purchase of a biofilter, because you can do it yourself.
To make internal biofilter for small aquariums, you will need:
- Plastic bottle;
- Awl or nail;
- Foam sponge;
- Filtering filler;
- Rubber bands;
We are starting to create a biofilter with our own hands:
- Burning awl at the bottom of the bottle along the entire circumference makes holes in 4-5 rows;
- We fill the aquarium biofilter with 2/3 bottles (a zeolite is recommended for biological filtration);
- We close the holes for water intake with a sponge so that the filler is tempered moderately;
- Fasten the sponge with two rubber bands to hold it on the bottle;
- Immerse the bottle vertically in the aquarium;
- Since this filter is designed to work on the principle of airlift, the sprayer is lowered inside the bottle;
- Purified water, saturated with oxygen, rises up the filter and goes into the aquarium.
The advantage of such a biofilter is its ease of operation and the fact that it can work with such a filler without cleaning for several months. You only need to wash the sponge regularly.
For a homemade biofilter for a medium-sized aquarium, it is necessary to resort to creating a more complex structure with three compartments for fillings.
For this we need:
- Transparent silicone aquarium;
- Fillers – foam rubber, sintepon and expanded clay;
- Glass sizes required;
- Glass cutter;
- Pure alcohol.
Simple aquarium biofilter
Now we collect our filter:
- We measure the length of the aquarium from the tie to the tie, as well as the width with a centimeter (in our case, the length was 27 centimeters, and the width – 12 centimeters);
- Cut the glass with dimensions of 27 × 12 cm using a glass cutter and a ruler – this will be the bottom of the filter;
- In the same way cut the side walls of the filter. We already know the length of the wall (12 cm), and take an arbitrary height (10 cm);
- Then we cut the glass for the back wall of the filter with a length of 27 cm and 8 mm (taking into account the thickness of one side glass 4 mm) so that it lies on the side walls. The height remains the same (10 cm);
- Before gluing the bottom, back and side walls together, degrease the edges of the glass with a cloth moistened with 99% alcohol;
- Insert the silicone into a special gun and apply it to the edges of the glass;
- We connect the glass to each other and wait about an hour for the silicone to dry;
- We cut a partition measuring 27 × 8.3 cm. We measured the height from a matchbox attached to the bottom of the filter so that the partition did not touch the bottom and the water would overflow from one compartment to the other at the bottom of the filter;
- We degrease and glue the first partition to the side walls at around 4 centimeters with silicone, since we will have 3 compartments for fillers, and the filter width is 12 cm. boxes do not remove;
- The second partition is glued to the bottom, but its height should be 2 centimeters lower than the height of the side walls of the filter. This is done so that the water from the second compartment to the third falls through the top.
- Therefore, we cut the second partition with dimensions of 27 × 8 cm;
- We degrease and glue the glass of the second partition at a distance of 4 centimeters from the first partition;
- After 12 hours, our future filter fully dried, after which we can remove the matchbox;
- We cut two partitions so that the water does not flow down to the ribs of the aquarium, on which the filter will be located. They should be wider than these ribs. In our case, we took dimensions of 10 × 3 cm, degreased the glass and glued it to the free side of the filter where water would flow;
- Cut a glass strip measuring 27 × 2 cm and glue it to the end of the second partition so that the water from the second compartment flows down in the middle of the third;
- We wait about an hour until the partitions and the plank dry out;
- Then we need a glass that will hold the sintepon in the third compartment. We measured the length of 22 centimeters, and the height of 7 centimeters, in order to leave a gap below and the sintepon was not blocked, allowing water to drain into the aquarium;
- Degrease and glue the partition;
- We cut another glass with a length of 22 centimeters and a width of 2 centimeters, degrease it and glue it under the gap at the outlet of the water into the aquarium. This will allow the water to flow down not into the filter, but immediately into the aquarium;
- We wait a few more hours until the silicone is completely dry;
- We fill the first compartment with foam rubber, the second with expanded clay, and the third with padding;
- We put the filter on the ribs of the aquarium;
- We bring the hose from the mechanical filter to the biofilter for filling it with dirty water from the aquarium and its further purification.
As a result, we have an external biofilter with three-level filtration, which is ideal for complete water purification in a 100-liter aquarium.
The fillers used here perfectly retain dirt and beneficial bacteria, which accumulate in them very quickly and soon purify running water from ammonia.