Internal filter V.S External filter

Why do I need a filter?

The filter is necessary accessory used for cleaning and regenerating the aquarium water. To keep it healthy, balanced, crystal clear and odourless condition. Also a filter removes waste produced by the fish, stopping water becoming polluted, which in trun could cause the fish ill or die.

Here we talk about the post popular internal and external filter.

What is internal filter?

A small submerged filter for small and Nano-sized aquariums. The filter system is equipped with a water pump, a small foam mechanical/biological filter and, where applicable, a charcoal canister.

internal filter

internal sponge filter

Pors of internal filter
  1. Affordable price, excellent for small tanks of water volumn under 50L ;
  2. Does not take up too much outer space;
  3. Water flow rate will not be affected;
  4. Small capacity, easy to maintain.


Cons of internal filter
  1. Filtration efficiency not good as other filters it is too small.
  2. It takes up space inside the tank;



What is external filter?

External filters usually fit into the cabinet under the aquarium connected by two tubes. Water is removed from one end of the aquarium, cleaned and then returned back to the other end of the aquarium via a spray bar or other spray nozzles.

Pros of external filter:
  1. Takes up some space for a high retention capacity;
  2. Powerful filtration treat water throughly;
  3. Keep balance water condition so that fish will be healthier;
  4. Easy to control it’s filtration performance.


Cons of ecternal filter:
  1. Set-up is a bit more technical with suction and discharge tubes;
  2. Manual start-up is a bit trickier
  3. A more substantial budget is required.



What is the difference between internal filter and external filter?


Internal filter: Internal filter is small whilst can fit any tanks

External filter: External filter can be large and takes up some space


Filtration efficiency:

Internal filter: good recirculation within water, have good effect at the beginning to use.,but will not last long

External filter: has a large filtering capacity and more advanced solutions to achieve a balanced tank.