Air Stones: The Secret Weapon Every Aquarium Needs

Having enough oxygen in your aquarium is one of those things people often take for granted, but it’s so vital to your fish’s health. How can you make sure your fish is getting enough air? Most fish will show signs of oxygen deprivation, such as a tendency to rest at the bottom of their tanks, a lack appetite, or rapidly moving gills. In a worst-case scenario, your fish may start gasping for air at the surface of the water, which means it’s definitely time to take action!

The first step is to do a large water change, which will immediately infuse the tank with fresh oxygen. If the fish immediately perk up, the second step is to determine why the aquarium was suffering from lack of oxygen. The most common causes are high water temperatures and too many fish in a tank, certain medication or chemical treatments, and inadequate water surface agitation.

How do I Get More Oxygen in My Fish Tank?

The dissolved oxygen content can be measured directly using a water test kit and digital meter. The ideal oxygen level for freshwater fish tanks should be between 7 and 8 ppm or mg/L. We ran several experiments with a dissolved oxygen monitor to determine the best setup for increasing oxygen levels in aquariums. Here’s what we found:

The experiment results for increasing dissolved oxygen in different aquarium setups

Note: Powerheads and circulation pumps were also tested, but the exact results were not recorded. The powerhead of venturi type did not perform as well than the powerhead pointed towards top of tank, which created surface agitation. The oxygen content was not significantly improved by a circulation pump.

Based on our experiments, we definitely see that increasing gas exchange at the water surface has a positive impact on oxygen content. Gas exchange in aquariums refers to the process where carbon dioxide, a waste product of your fish, is released into the air and new oxygen is dissolved into water. These are the three most effective ways to increase oxygenation within your aquarium.

– Buy tanks with a large surface area. When using only a sponge filter in the 40-gallon tank versus 55-gallon tank, the 40-gallon tank had much higher oxygen content. The reason is because the 40-gallon breeder tank has a greater amount of surface area compared to the 55-gallon tank. Therefore, a long, shallow aquarium is preferred over a tall, narrow one.

– Don’t let floating plants cover the water surface. When using a sponge filter in the 55-gallon tank, the experiment with floating plants had significantly less oxygen compared to the experiment without them. In general, live aquarium plants can be very useful in producing additional oxygen for your fish. However, don’t let floating plants take over your entire tank because it limits the amount of gas exchange.

Too much floating plants can significantly reduce oxygen levels within your fish tank.

Increase surface activity with filtration and stones. Gas exchange is the process where carbon dioxide in water is replaced by more oxygen from the atmosphere. One of the best ways to do this is by adding at least one air source (like an air stone or sponge filter) to every aquarium, no matter what other filtration you’re using. You can achieve good surface agitation using other methods like a hang-on-back filter, but it comes at the cost of having very loud splashing sounds from the falling water.

How to Add Air to Your Aquarium

Adding an air source to your fish tank is very easy – all you need is an air pump to push air into the water, airline tubing for the air to travel through, and a check valve to prevent water from flowing into the tubing.

How do you attach an air pump to an aquarium?

Those three components reside outside of the aquarium, but the last bit of airline tubing (on the left-hand side) enters the water. You can attach a variety of attachments to the aquarium’s air tube.

An water stone is small, weighted bubbler that makes very small bubbles in the drinking water. This accessory is simple and helps to diffuse the air into your tank, reducing the volume of bubbling sound.

– A sponge filters use air to provide biological and mechanical filtering. The sponge walls allow water to pass through the sponge walls and remove waste particles. Beneficial bacteria likes to live in sponges, which helps to transform waste compounds into safer byproducts. A moving-bed filter provides the ideal environment for biological filtration. As the air flows through the chamber, oxygenated water is constantly churned. This greatly increases the growth of beneficial bacteria.

Add more air to your aquarium using an air stone, sponge filter, or moving bed filter.

All these methods of adding air to your fish tank promote excellent surface agitation and oxygenation of water, providing an ideal, stress-free environment for your fish to live in.