Hang on back filters have been a part of this hobby for a long time. They have done great providing filtration and they continue to help clean our aquariums. Many curious aquarists want to know whether hang on back filters provide oxygen. The simple answer is yes they do provide oxygen to your aquarium. I’ll go into detail how it accomplishes this.
Where Does the Oxygen Come From?
Your filter system helps move water around your fish tank. Every hang on back aquarium filter I have seen creates a waterfall that outputs water back into your aquarium. This is the source of where oxygen is produced. The water formed by the waterfall comes in contact with the air. While it’s flowing into your aquarium, it “catches” small oxygen particles out of the air, which then go into your aquarium. Oxygen exchange does not stop there either. When the water from the filter comes in contact with your aquarium water, it creates a ripple. Just like the waterfall, these ripples grab oxygen out of the air and add them to your aquarium.
To get oxygen into your fish tank, it is important to have something whether it’s a filter, air pump, or circulation pump breaking the water’s surface. You will get the most oxygen exchange there.
What About Air Pumps?
The bubbles formed by air pumps do not produce high amounts of oxygen for your fish tank. Most are simply to big to be absorbed by the water. Just like a hang on back filter, the air pump creates ripples in the water when the bubbles reach the surface. The ripples will catch oxygen out of the air and add it into the water. Generally, you do not need an air pump for your aquarium if you have other equipment breaking the water’s surface. However, most aquariums benefit from more oxygen, and an air pump is a great way to accomplish that.
Final Notes
A hang on back aquarium filter is a versatile piece of equipment that does many things. They provide filtration, water circulation, and assist in adding oxygen to the aquarium. I have enjoyed using HOB filters in many of my aquariums, and will continue to do so. If you are on the hunt for a HOB filter, check out 7 Best Hang On Back Filters for Freshwater Aquariums.