How to Increase Water Circulation in Your Aquarium

In saltwater aquariums, water circulation is often discussed to imitate waves. But freshwater aquariums can suffer from a lack flow. Fish tanks (especially large ones) with lots of decorations or hardscape can develop dead zones where lots of debris collects and algae starts to grow. Increasing water circulation can help (a) stir up waste particles so they get collected by the filter, (b) evenly distribute nutrients for aquarium plants to consume, and (c) improve surface agitation so that fish have enough oxygen to breathe. Some species, such as rainbow shiners or hillstream loaches, are used to living near rivers and may be more comfortable with higher currents. This article will discuss how to increase water circulation in your aquarium.

Water Circulation for Gentle Flow

If you have a smaller fish tank and/or only need slow to normal amounts of flow, then a regular aquarium filter can provide sufficient current for your needs. You can read our guide to fish tank filters about the many types of filtration – such as sponge, hang-on-back (HOB), and canister filters. These options can be used to filter and clean the water as well as create current and surface agitation. Moving water at the top of the aquarium is important because it prevents oily biofilm from developing on the surface and encourages good gas exchange, where carbon dioxide (exhaled by your fish) is released into the air and new oxygen (for the fish to breathe) enters the tank.

If you have baby fry or a betta fish with long flow fins, sponge filters are one of the gentlest filters on the market. Canister and HOB filters are stronger options. They use motors to move water and have an adjustable flow valve that can increase or decrease output speed. A simple air pump and air stone can be used to increase flow in stagnant corners of the tank. The bubbles in the air stone create surface agitation by rising water and moving it as they do.

If you have slow-moving fish or baby fry, a sponge filter can provide sufficient water circulation without stressing them out.

Water Circulation for Faster Flow

For larger aquariums or fish tanks that need faster flow, a power head is great option because of its versatility in multiple applications. A powerhead simply refers to a submersible water pump. It takes water from the input, and pumps out a strong stream of water from it. This device can be used to speed up water changes, create your own DIY filtration, and of course boost water circulation in your aquarium.

The Aquarium Co-Op power head circulates over 200 gallons per hour and has an extra-long, 11.8-foot power cord to reach almost any outlet.

How big of a power head do I need? Some websites say that water should circulate around a tank at least four times an hour, so if you have a 100-gallon tank, then you need a filter and/or powerhead that can move 400 gallons per hour (GPH). Our experience shows that aquariums have different flow rates depending on their species. Some species are unable to handle strong current and can become sick. If you see that your fish and foliage are being whipped around the tank, choose a less powerful filter or power head. To decrease the kinetic energy, you can disperse the flow with a spray bar or direct the flow into a wall.

How many watts does a powerhead use? Each model is different, but the Aquarium Co-Op power head uses 10 W of power to produce 211 GPH or 800 liters per hour (LPH).

A power head can be used to filter water. Many people use them to transfer water from their aquarium sump filter (which is a type of custom filtration) back into the fish tank. Our powerhead pump was also made to work with Aquarium Co-Op sponge filters. An air pump is typically used to run a sponge filters and draw water through it. Attaching a powerhead to the sponge filter will allow water to be pulled through the foam at higher speeds. This results in better mechanical filtration and clearer waters. Although this can clog foam faster so it is more difficult to clean, Aquarium Co-Op sponge filter are made from coarse foam that is not as easy to block.

Attach a power head to the uplift tube of the sponge filter to strain particles from the water at a faster rate.

What’s the difference between a powerhead and a wave maker? A fish tank powerhead typically shoots a narrow jet of water in one direction, whereas a wave maker is meant to imitate the back-and-forth motion of ocean waves.

My Powerheads Where Do I Place Them?

You can find dead spots in your aquarium’s water by looking at where the algae is growing or debris is accumulating the most. Using a power head can help disperse the decaying organics in those stagnant regions so that they get sucked up by the filter, thus making your water clearer overall.

If your heater has a “low flow” indicator that constantly goes off, consider putting the power head near it so that the heated water can spread throughout the rest of the fish tank and eliminate any hot or cold spots.

We like placing our power heads near the top of the aquarium so that they prevent oil slicks and agitate the water surface. If the pump is too close to the ground, it could cause water cloudiness and stir up the substrate. If you want to hide the power head, try blocking it with a fish tank decoration or tall plants. Black backgrounds can also be used so the aquarium’s back looks better.

Ideally, place your power head in a location that targets stagnant areas while staying relatively out of sight.

It could have become clogged with time and reduced the output of your powerhead pump or aquarium filter. Follow the instructions on the manual to clean it. The performance will return to normal. Check out our Aquarium Co-Op powerhead for more information. It will keep your aquarium ecosystem healthy through proper water circulation.