How to choose Aquarium Filters

Aquariums Filters are most important part, which support life of Fish in Aquarium , aquariums have no natural  filtration .so we have to use some Filters which will remove harmful chemicals
like nitrates , ammonia and also waste product left when fishes eat , or left food .it also helps in moving a water in aquarium, which is also important factor .

There are lots of filters, some of them are as follows:

Biological Filter :- Biological filters controls Ammonia,nitrate,mainly it is sponge ,and gravels, the larger part of the sponge gives the space for the development of colony of bacteria which is very useful in growth of bacteria, this bacteria convert nitrates into Nitrogen gas , some bacteria are useful in growth of fish. Biological filters do two works first they remove ammonia and second breaks nitrates into notrogen gas. The reason why mostly the new aquarium fishes dies is due to lack of bacteria in water.so we should use  filters which helps in the growth of bacteria.

Some of the Biologiacl filters Are

1. Under gravel Filter 
2. Bio Wheel Filters
3. Canister Filters
4. Fluidized Bed Filters

Mechanical filters :- Mechanical filters are manily contains pump which inputs the water from the filter ,filter can be gravel,sponge, Activated carbon etc, which  helps in removing the waste products from the water.it can be both biological filter or chemical filter.

1. Bio Wheel Filters
2. Canister Filters
3. Corner Filters / Box Filters

Chemical filters :- this are some chemical used for cleaning the water in emergency or if u don't have Biological filters or mechanical filters, but it should be used under the guidance of shopkeeper or doctor.

Protein skimmer :- The Protein skimmer are used to remove Protein and Ammonia,without using any chemical. This filter must be used by Aquarium hobbyist who wants to grow coral reefs , because only this is the safe filter to remove Ammonia without increasing the algae and it also removes waste before breaking into Ammonia.

I recommend Biological filters , because its not only remove waste product it also helps in breaking Ammonia and nitrates .Bio Wheel Filters are really awesome. And if you have corals reefs then i will recommend Protein skimmer.