HomeWhy is it necessary to maintain a healthy aquarium? What is a physical environment?Why do fish need space?

Why do fish need space?
      It is very important that the fish have enough space in the aquarium to survive comfortably. Space is important for the fish in the aquarium ecosystem for two reasons:
Fish breathe oxygen that is dissolved in water;
Fish need space in order to grow and to mate.
     If there is too many fish and not enough space, the fish will not have enough oxygen to breathe. Over crowding will also cause the waste products to build up and will make the water dirty.

Why does an aquarium need a good source of oxygen?
Why is it necessary to remove the waste products from the aquarium?
Why do fish need space to reproduce?