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. Additionally, certain species such as hillstream loaches and rainbow shiners are used to living in rivers that flow quickly and may benefit from more current. 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. Each of these options is good for filtering the water and creating surface and current 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. In cases where you have adequate filtration but need a little extra flow in a stagnant corner of the tank, consider adding a simple air stone with an air pump. The bubbles from the air stone move water as they rise and create surface agitation when they pop.

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 powerhead circulates more than 200 gallons an hour and has a 11.8-foot extension cord that can reach nearly any outlet.

What size powerhead do I need? According to some websites, water should circulate around the tank at least four times per hour. If you have a 100-gallon tank you will need a filter or powerhead capable of moving 400 gallons an 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.

What wattage does a powerhead consume? Every model is different but the Aquarium Co-Op powerhead uses 10W to produce 211 GPH (or 800 liters an hour) (LPH).

Can a powerhead be used as a filter in my filtration system? 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. Normally, an air pump is used to run a sponge filter and gently draw water through the foam material. A power head can be attached to the sponge filter. It will pull water through the foam at higher speeds. This allows for greater mechanical filtration. Clearer water can also be obtained. The method can potentially clog the foam more quickly so that you have to frequently clean it, but Aquarium Co-Op sponge filters are made with coarse foam that does not become obstructed as easily.

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.

So that oil slicks are prevented and the water surface is agitated, we like to place our power heads near top of the aquarium. The pump should not be placed too close to the ground as it can stir up the substrate, causing cloudy water. 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.

Place your power head where it targets stagnant areas, but keep it out of sight.

You may notice a decrease in the powerhead pump or aquarium filter’s output. This could be due to clogging. Follow the instructions on the manual to clean it. The performance will return to normal. To keep your aquarium ecosystem healthy and ensure proper water circulation, you can check out the Aquarium Co-Op powerhead.