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. Plus, some species like rainbow shiners and hillstream loaches are used to living in fast flowing rivers and may appreciate greater current in their environment. 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. All of these options are good for not only filtering and cleaning the water, but also creating 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. You canister or HOB filters, which use motors to move the water, are a stronger option. These filters often have an adjustable flow control to adjust the flow rate. 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 created by the air stones move water as they rise, and cause surface agitation when their bubbles 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 for water changes, DIY filtration, or to boost the circulation of 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.
How large a powerhead should I get? Websites state that water should be circulated around a tank at a minimum of four times an hour. This means that if your tank is 100 gallons, you need a filter/or powerhead that can move 400 GPH (gallons per hour). 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 much power does a powerhead need? The Aquarium Co-Op powerhead produces 211 GPH, or 800 liters per 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. The powerhead pump is designed to be compatible with Aquarium Co-Op sponge filter. Normally, an air pump is used to run a sponge filter and gently draw water through the foam material. By attaching a power head to the sponge filter instead, water is pulled through the foam at higher speeds, resulting in greater mechanical filtration and clearer water. 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 powerhead to the uplift tube at the sponge filter to remove water particles faster.
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.
Where Should I Place My Powerheads?
Locate the dead spots in your aquarium by observing where debris is collecting the most or if blue-green algae is growing in certain areas. A power head can be used to disperse any decaying organics that have remained stagnant. The filter will then absorb them, making your water cleaner 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. When the pump is placed near the ground, it may stir up the substrate and cause cloudy water. If you want to hide the power head, try blocking it with a fish tank decoration or tall plants. A black background can be used to blend in with the back of your aquarium.
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. Simply follow the instructions in the manual to clean it out, and the performance should return to normal. Check out our Aquarium Co-Op powerhead for more information. It will keep your aquarium ecosystem healthy through proper water circulation.