Aquariums - Part 1

Controlling Fish Population in Aquariums

Keeping the fish population under control is a necessary part of having a good aquarium. While it may seem difficult to get fish to breed in initial stages of an aquarium. Once the right conditions are made available, it is difficult to stop fish from breeding.

Fish breed in large numbers. Live bearers such as guppies and platies give birth to about 15 to 30 young ones while egg-laying fish such as goldfish, bettas produced hundreds of young ones.
In the wild, the population is kept in check by natural predators and the scarcity of food. However, in the aquarium food is plentiful and predators are absent. Thus, the population will start to increase in the aquariums. Thus, there is no way of keeping the population in check. This results in overcrowding and disease.

Hence, it is necessary to control the population of the aquarium.
There are several methods of keeping the population in check


Selling fish

This is one of the best ways of regulating the number of fish. This also helps you make some money out of your hobby. While newborn fry cannot be sold. Fish that are a few weeks or months old can be sold. If you have space for a few more tanks you can use them to raise the fry.


Keeping the males and females separate

This can be done only if you have more than one tank. Some hobbyists stock their tank with fish belonging to only one gender. This, however, is unnatural and can stress the fish as it disturbs the natural routine.

Introducing one or two large predator fish
Large Predator fish can eat up the small fry. This ensures that only a few number of fish survive.


Decreasing plant cover

Small fish hide in the plants. Removing the plants in your aquarium will result in the small fish getting exposed to predators.


Stocking the Aquarium evenly

Stocking your aquarium evenly is important as it ensures optimum use of the aquarium space and a pleasant viewing experience. Fish live at different levels in the water. Hence, selecting fish which occupy the top, middle and lower level of the aquarium ensures that all the fish have more space. This prevents fights and injuries.

Fish such as hatchetfish, zebra fish are top dwelling fish. Their mouths are upturned as they feed from the surface.

Fish such as guppies, swordtails, tetras are middle level fish. They swim in the lower levels. Gouramis are also another popular middle level fish.

Bottom dwelling fish have mouths which are turned downwards. These fish scour the bottom of the tank for food. Examples include loaches, cory catfish and the pictus catfish.


Selecting a net for your aquarium

Selecting a net to catch fish is important. A net should be big enough to catch the fish without injuring it. It should also be small enough for easy movement through the aquarium.

Nets are available in a wide range of shapes and sizes. There are square nets and round nets. There are nets which are fine and nets which are coarse. Coarse ones are ideal for big fish. Coarse nets can damage the fins of small fish which can get caught in the small holes.

If you have a rectangular or square tank, a rectangular net will be useful as it can fit better against the corners. If you have circular tanks, you can use circular nets.

When trying to catch the fish, position the net close to the fish without startling it. This will help prevent the difficult chases across the aquarium which can damage the plants and other fitments.

Some people lower the water level when they are catching difficult fish.

Another technique is to use two nets and drive the fish into one using the other.

Air Powered Filters in Aquariums

Air Powered Filters are filters of small capacity which are ideal for small aquariums. These filters do not require any external power source. They are driven by the air flow from the pump.

The air is allowed to rise through a tube which drives the water upwards. This causes a suction effect in the bottom. The water from the surrounding areas enter the tube through a sponge which filters the water.

The sponge material also serves as a medium for the beneficial bacteria to grow. Thus, it also acts as a biological filter.