Your fish needs to breathe just like you do. While you live in a home that is well ventilated, your fish are cramped into a tank that holds limited amount of water. The least you can do is to get a good aquarium filter for your tank.
Why you need an aquarium filter?
It is a common myth that fish can breathe in the oxygen that dissolves in water. However, that amount is very small and sufficient only if you have a single or few fish in your aquarium. Real aquarium plants also helps but only to a certain extent and that too only for small fish.
In all other circumstances you need an aquarium filter. However, you cannot use just any filter; it needs to be suitable for the type and size of your fish tank.
How To Choose The Right Aquarium Filter?
1. Aquarium Bubbles: If you have a small tank with 2 to 4 fish then you need not want an electronically operated filter that pumps the water. The lower version oxygenation is done by bubbles in your aquarium. The bubbles in aquarium keep turning the water but does not clean it. So your fish can breathe but in dirty water.
2. The Pumping Filter: A big tank with a lot of fish needs a powerful aquarium filter. This filter not only pumps the water fast, but also cleans the filth. More the fish, the dirtier your tank will be. So, if you don't want to clean your tank twice a week, install a filter.
3. Water Temperature: This filtration is required for cleaning, oxygenating and also for maintaining the water temperature. Like tropical fish cannot stay in cold water. So, for such fish pumping makes the water tolerably warm.
4. How Strong Is The Pump? When you use an aquarium pump, the water does not remain still. There is some current in it. Not all fish can swim comfortably in the current. If your tank has a combination of large and small fish, then it is better to regulate the pump to a minimum force. Try putting some aquarium plants to supplement oxygen for small fish because they may even get sucked into the filter!
5. Are Your Fish Breathing? If you see that all your fish are crowding at the top of your tank then it means trouble. This means your fish are not able to breathe and thus they are trying to get oxygen from the top layer of the aquarium where the water meets the air.
It is essential for your fish to breathe and thus, you must choose the right filter for your tank.