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Why Have An Air Pump On A Fish Tank

It is very common to buy an aquarium in the store as a package deal where you get everything you need in one box so it becomes a plug and play type of system and the learning curve is lessened due to not having to work out what equipment you need to set up a fish tank. It is very un-common however to get an “off the shelf” solution and it comes with an air pump and air stone so we wanted to explore why this might be and whether it is something that is essential for your fish tank.


The short answer is that an air pump is not essential to keep a successful and healthy aquarium however in some instances it is greatly beneficial. So we need to establish why an air pump is used at all and what it actually does. The air pump in an aquarium will generally pump air from outside the tank to inside the tank through an outlet. This outlet might be of ornamental and aesthetic value to you such as a coral which opens up to let bubbles out or a car or boat which you like the look of. It might simply be output through a hidden air stone too. Either way the effect is the same.


The purpose of an air pump on an aquarium is to oxygenate the water. Some think this is down to the bubbles passing through the water, this has very little effect though and it is actually due to the surface movement which the bubbles create which makes a difference. The more surface water movement you have, the more contact the water has with the air and so the more oxygen gets in to the water. This effect can be gained from a filter outlet or a powerhead. The filter outlet must be pointing in the right direction, we have discussed the various options in an article about filter outlet direction options here.


The fact that this beneficial effect is the same beneficial effect which you get from the filter outlet is the reason why an air pump is not included in a standard aquarium package bundle which you might see in your local fish shop. It is taken care of by the filter outlet.

So why would you have an air pump on an aquarium if the filter outlet takes care of the water oxidisation? This is simple and all down to having the added back up of another product doing a similar job. We spoke previously about doubling up on equipment for your fish tank, this could be seen as a similar concept. It might also be down to wanting to help break down any film or layer you might have form on the top of your fish tank which could look like an oil slick. This layer prevents the oxidisation of the water and can sometimes only be broken down using an air pump. If this is the case then there is a strong chance you are over feeding but we have covered the possibilities and cures for a fish tank surface film in another article.


You might simply want to have bubbles in your aquarium because you like the look of them. Best thing to remember is that they can’t do any harm and can only do your fish and aquarium good so it is recommended that you install an air pump and air stone in your fish tank, even if you have it on a timer switch so it is not on 24/7.