Why Use a Circulation Pump for a Fish Tank?

Two words in this hobby that get used interchangeably but are technically two different things are circulation pump and powerhead. Even companies use the words Powerhead and circulation pump interchangeably which can confuse people. Both have quite a bit of overlap in terms of what they do but there are key differences. At the end of the day, they both move water around an aquarium. I’ll briefly discuss what both technically are but for the sake of this article, I will use both terms interchangeably. This article will discuss why you might want to use a powerhead/circulation pump in an aquarium.

What is a Circulation Pump?

A circulation pump is technically a pump that can be used to pull water out of a sump system and into the display aquarium. Some might know them better as return pumps or sump pumps. The Hygger 24V Water Pump (Affiliate Link) is a great example of a circulation pump. The pump sucks water through the intake. The output end is usually connected to PVC piping or flexible tubing that discharges water into the aquarium. Some circulation pumps can be converted into powerheads but most do not have that capability.

What is a Powerhead?

A powerhead is a piece of equipment that moves water around a fish tank to increase flow. Think of it as an underwater fan that blows water around to create a current. There’s not much else to it. Unlike a circulation pump, a powerhead cannot push water through pipes. The Hydor Koralia (Affiliate Link) is probably the most iconic powerhead brand but there are many more great ones out there. In the next part of the article, I will discuss some uses for powerheads.

Remove Dead Spots from the Aquarium

Dead spots in aquariums are spaces where detritus can settle. Water flow doesn’t reach this space so it’s a perfect space for debris to rest, which can become a nutrient farm over time. A filter normally moves water around and removes debris from your aquarium, but sometimes your filtration could use a little help from a powerhead. Dead spots are inevitable, and in small quantities, they’re not always a bad thing. They’re a space fish can use to rest from current and water movement. So it has its benefits to some extent.

Add Flow For Coral Reef Tanks

Corals thrive on water movement. Different corals benefit from different levels of flow. For example, leather coral enjoys very calm flowing water. Others, like LPS and zoanthids, can tolerate moderate amounts of indirect flow. Lastly, stony corals love high flow, and large colonies can die off if not enough water movement gets through the intertwining branches. Filtration systems help with water movement, but that’s usually not enough for larger saltwater aquariums. The powerhouse that moves water around in a reef tank is often the powerhead.

To Mimic an Ecosystem

This more or less bounces off the previous statement. To imitate a coral reef, you need varying levels of flowing water to replicate the changing movements of water. You will not get a successful reef tank without any water movement. Live rock is part of the filtration system in a coral reef, and water must move in and out of it to do its job successfully. Corals will utilize water movement to filter feed. Without moving water, nutrients and food will never reach them.

You can add flow to your aquarium with circulation pumps to mimic a river ecosystem. There are wonderful examples of fish keepers mimicking this type of environment using this equipment. Check out the video below of this exact example.

Mixing Marine Salt For Water Changes

I remember the days when I would manually mix saltwater before doing water changes. Luckily, I have grown in the hobby and made it easier for myself with an old circulation pump I had lying around. I add salt into a bucket, add RO water, and toss a circulation pump into the bucket to start churning the water. This allows me to set and forget this part of the water change.

I check up on it from time to time to make sure salt hasn’t settled in a dead spot in the bucket. If it does, I shift the powerhead to move the water from a different direction. It’s a nice trick I use to give me a little more time to do things before a water change.

Final Notes

There are probably countless other ways to use powerheads in an aquarium. They’re a fantastic tool to use to create a unique ecosystem for specific species of fish, useful to make your aquarium maintenance easier, and the most obvious to aid in moving water around a fish tank. If you have other fantastic ways to use powerheads, consider taking the time to share them to help make this hobby great!