Hepper is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

How to Aerate Water Without a Pump – 6 Methods

Lindsey Stanton Profile Picture

By Lindsey Stanton

aerated water bubbles

Having good aeration in your fish tank is pretty crucial. Just like us humans, fish need to have air in the water to breathe. Without enough oxygen dissolved in the water, fish can’t breathe, which is of course not a good thing at all. However, getting enough aeration going in the aquarium can be a little tricky, especially if you do not have an air pump.

Maybe there is not enough room in your aquarium for an air pump, maybe you cannot afford one, or maybe you just don’t want one. At any rate, how to aerate water without a pump is a problem that is actually easily solved, so let’s talk about it right now.

wave divider

Aeration vs Oxygenation

One of the things that you need to know about first is the difference between aeration and oxygenation. Oxygenation is how much oxygen is dissolved in the water, plain and simple. However, aeration is a little different. Aeration does involve oxygenation, but it also involved water flow. Aeration is the amount of oxygenated water moving around in the tank.

In other words, the movement of water throughout the tank will determine the overall aeration. For example, oxygenators will add more oxygen into the water, but they do not really disperse it due to having a low rate of flow.

However, aerators produce oxygen while also having lots of water flow, thus aerating a fish tank. Of course, having a fish tank that is not properly aerated is pretty bad because your fish won’t be able to breathe properly, but what if you don’t have or want a pump?

aquarium plant divider

The 6 Ways To Aerate Aquarium Water Without A Pump

There are some things that you can do in order to increase the overall aeration of your tank.

Follow these tips below in order to get the job done;

1. The Cup Method

One of the easiest ways to aerate the water in your aquarium without a pump is to use a pitcher or cup. Simply fill a pitcher or cup with the aquarium water, lift it up nice and high, and pour the water back in. The water will pick up oxygen on the way down to the tank, thus inserting oxygen right into the water. The higher up you pour the water from, the more oxygen it picks up along the way.

Also, the higher up you pour the water from, the deeper it will travel into the depths of your tank, thus aerating the water. You might want to place a plate of some kind at the bottom of the tank so you don’t stir up too much substrate and debris when pouring water into the aquarium.

2. A Good Filter

The filter you have can also make a pretty big difference. If you do not have an air pump, the filter you have is probably going to be the primary means of oxygenation and aeration for your aquarium. Simply put, a powerful filter will generate some oxygen as the water flows through it. At the same time, the water coming out of the filter gets delivered into the aquarium.

The higher the flow rate of the filter and the higher the water pressure of the water coming out of it, the better aerated the water in your aquarium will be. Make sure that you have a fairly powerful filter and one that is clean. The cleaner your filter is, the more water can flow through it, and the more oxygenated and aerated the water will be (we have reviewed our top 11 favorite filters over at this article).

fish tank filter pip and little fish
mariait, Shutterstock

3. Spray Bars & Waterfall Filters

You can also use things like a spray bar or a trickle filter, such as a waterfall filter to achieve good water aeration. The water coming down off of the spray bar or waterfall filter picks up oxygen as it falls down into the tank.

Also, because the water flows down from a certain height, it will propel the water down into the tank, thus creating a well-aerated environment.

4. Plants

One of the easiest ways to make sure that your fish tank has enough oxygen and aeration is to insert more plants into the water. You want to insert plants that eat up a lot of carbon dioxide while also producing a lot of oxygen. Plants go through photosynthesis, which is what they do to live, the conversion of CO2 into oxygen. So, the more plants you have in the water, the more oxygen is created.

Now, plants obviously do not produce any kind of water flow or movement in the water column, but this is not very important because the plants are already spread out along the bottom of the tank. The water flow is not so important because the plants are already in the places where the aeration needs to be.

Keep in mind that plants do the opposite of photosynthesis when the lights are off. So, if you have the lights off too much, a large number of plants can actually decrease the amount of oxygenation and aeration in your tank.

orange fish in tank with plants
Image credit: Unsplash

If you want your fish to breathe properly but you’re unsure of exactly how to create the best aeration setup in your aquarium, you should check out our best-selling book, The Truth About Goldfish, on Amazon. It covers everything about tank setup and maintenance for all types of goldfish housing!

The Truth About Goldfish New Edition

5. Fish

Ok, so this may seem a little odd, but adding more fish into the aquarium can indeed increase the aeration of the tank. Yes, fish do breathe oxygen, so they do not increase the amount of oxygen in the tank. In fact, the more fish there are, the more oxygen is being used up. However, as we mentioned before, aeration and oxygenation are not exactly the same things.

If you have lots of really active and fast-moving fish in the water, their movement will serve to mix the water around. Their movement will carry oxygen-rich water from the top of the tank down to the depths. This may seem like it goes against common sense, but it really doesn’t.

6. Wide & Shallow

Another way in which you can increase the oxygenation in a fish tank is by buying the right tank in the first place. Water always has a higher oxygen content near the top, you know, where it touches the air. So, if you have a really deep and narrow aquarium, but no air pump, only the top of the water will be well oxygenated and aerated.

However, if you have a tank that is wider and not so deep, there is more water area that is touching the air above. Therefore, the wider the tank is and the more surface area there is for the water to touch the air, the more oxygen the water will have, and in turn, the tank will be much better aerated.

close up of aquarium tank_Solarisys_shutterstock
Image Credit: Solarisys, Shutterstock


divider: bubbles


Oxygenation and aeration are both integral parts of any aquarium. If your fish tank is not aerated well enough, but you don’t have a pump, you can try any of the above methods to improve the situation. Heck, you can try a combination of any of the above methods.

Related Articles

Further Reading

Vet Articles

Latest Vet Answers

The latest veterinarians' answers to questions from our database