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.