Water flow in a reef aquarium is absolutely crucial to create a healthy environment for the animals inside the tank. Wild reefs are naturally very turbulent and creating natural flow patterns will help keep debris suspended in your tank, promote proper gas exchange, and help deliver food and nutrients to your tank inhabitants. When building a reef tank, submersible pumps often called “powerheads” are used to create water movement inside the tank.  In this video we are going take the guesswork out of shopping for powerheads and show you guys how to choose the appropriate powerheads for your tank.

First and foremost, I should probably note that using powerheads is not the sole source of water flow in most reef tanks.   For this video, we will be discussing internal water movement which only applies to powerheads or internal wavemakers.  Choosing a return pump and gauging return water flow through your filtration should be addressed separately and you can check out our video below for more information:

When looking at powerheads you will notice a couple of different basic styles. You have wide flow type “propeller” powerheads such as the Hydor Koralia, EcoTech Vortech, Neptune WAV and Tunze Stream Pumps which are great options for moving water inside a reef tank.  They move a large volume of water at a lower velocity making it much easier to get water movement in every nook and cranny of your tank.  The flow patterns produced by these wide flow type powerheads is also very natural and the most popular choice for reef tanks.

You will also see the classic jet stream style powerheads such as the Cobalt MJ powerheads and Taam Rio powerheads.  These powerheads can produce a very strong stream of water flow but the output is very focused. To learn more about the versatility of MJ pumps, check out this video:

A new cross-flow type of “powerhead” was introduced by Maxspect to the aquarium hobby a little over a year ago. The MaxSpect Gyre produces a laminar water flow pattern that is very unique and has several unique benefits compared to traditional powerheads. You can find out more about the Gyre by watching this video:

When sizing a powerhead, you need to take into consideration the size of your tank and the type of corals you plan to keep.  When keeping a tank that is predominately Soft Corals and LPS, you want to accomplish a total tank turnover of 10-20 times per hour.   When keeping SPS corals, your target turnover should be 20-40 times per hour.   For example, if you have a 50 gallon SPS dominant aquarium; you want to have a total internal flow rate of 1000 – 2000 GPH coming from a wide flow type powerhead.

Once you figured out how much flow you need, now it’s time to think about pump placement. Ultimately, you want water to be moving in every inch of your aquarium leaving no room for stagnant water or dead spots in the tank.   Depending on the shape of your aquarium and your aquascape, it is often a much smarter choice to purchase multiple smaller powerheads as opposed to one large powerhead.

Therefore, if you are trying to accomplish a total flow rate of 2000 GPH, you will want to choose two powerheads that are rated at no less than 1000 GPH each.

By using two or more smaller powerheads you can position the pumps in such a way to maximize water movement throughout the entire tank without creating a sandstorm.  It is also much easier to move the pumps around if and when your flow requirements change.

As a tank matures, corals will grow and additions will be made to the tank so you will need to re-direct your water flow to accommodate these changes; having multiple powerheads makes it much easier to get the flow into the areas of your tank that need it most.  If you find that there are stagnant areas in your aquarium after the addition of powerheads, a smaller powerhead, such as the Hydor Koralia Nano, can be used to target those problematic areas.

With such a large variety of powerheads we offer, it is easy to find a powerhead or a combination of powerheads that is perfect for your aquarium and your budget.

If you found this video helpful, please like and share to help out other hobbyists.   We appreciate all of you for watching and until next time, take care and happy reefkeeping.