Generally, the covered aquarium itself has filtration, but because the filter box is relatively small, it can not play a big role in maintaining water quality. If you want to change the filter, you can consider changing a larger filter box, so that you can put a variety of filter materials inside. Of course, if you are worried that the new filter box does not match the original fish tank, you can also add an external filter barrel directly.
1, bottom filter: bottom filter can be said to be the best filter, itself will not take up additional space, but placed at the bottom of the fish tank, and the filtering effect is very strong, because there are many filter materials that can be placed. However, the bottom filter is only suitable for larger aquariums, if the size of itself is small, using the bottom filter is somewhat wasteful.
2. Upper filter: Upper filter is also a common filter device. Compared with bottom filter, it is more convenient to install and clean, but its filtering capacity is relatively limited. Moreover, because it is placed above the fish tank, it does not look very beautiful, and it will lead to long-term uneven stress in the fish tank, which will easily increase the risk of cylinder explosion.
3. Filter barrel: The external filter barrel is also a good choice. Because it is placed outside, there is no need to worry about the problem of affecting the interior of the fish tank. The filtering capacity of the fish tank itself is also OK, and it is also very convenient to clean.
