When it comes to aquarium pumps, you have basically two camps. AC pumps are those water pumps powered by alternating electrical current and have been moving water in aquariums since the very beginning. They operate at a constant speed and will often transfer some level of heat into the aquarium water. DC pumps are a little different in that they are powered by a direct electrical current which allows for the control of the pump speed. By reducing or increasing the current into your DC water pump, you can control how fast the impeller spins and, therefore, the flow rate.

DC water pumps run quieter and cooler compared to AC pumps and ultimately consume less electricity per GPH. They also have a controller which gives the user flow control and allows for more advanced control such as a feed hold, float switch protection, and direct connection to an aquarium controller.  Some of the most advanced DC pumps come Wifi enabled which means you can access and control the pump using an app on your phone! 

6 Ways To Use a DC Water Pump on Your Saltwater Tank

The controllability and efficiency are probably the biggest benefits of using a DC pump over an AC pump because these two features are particularly beneficial across of wide variety of applications making DC pumps incredibly versatile. 

1. Return Pump

This is the most obvious application where the benefits of a DC pump are most appreciated. Having flow control means you can easily tune your overflow for ultra-quiet operation and quickly set your tank into a "feed mode" by temporarily shutting down the pump with the push of a button.  The lower electrical consumption and minimal heat transfer reduce the overall carbon footprint of your aquarium and ultimately saves you money in operating costs.  

2. Protein Skimmer

Control is the biggest benefit here because a DC pump gives you an extra precise adjustment over your skimmer's performance. Protein skimmers are adjusted based on the level of dissolved nutrients in the aquarium water. By adjusting the water flow directly you can control how much air and water are mixed together which essentially means you can accommodate a wider range of nutrient levels.  AC pump skimmers are limited with a fixed flow and water level adjustment which narrows the range of nutrient levels the skimmer can target. In a nutshell, DC pumps make it easier to dial in your protein skimmer for optimal nutrient export. 

3. Media and Algae Reactors

DC pumps work great for media reactors because you can adjust the flow-through rate to accommodate the particular reactor and media you are using. Carbon and GFO reactors use require relatively slow flow rates whereas a macroalgae reactor or biopellet reactor would require stronger flow. 

4. Saltwater Mixing Station

This is nice because you can quickly turn the pump on/off using the controller which comes in handy during water changes and when filling buckets.  Avoids that classic conundrum of not being able to hold the hose in the bucket while reaching the pump plug.  

5. External Plumbing

DC pumps are suitable for both submersible and external applications meaning you can use them to feed into a manifold or closed-loop system.

6. UV Sterilizers

UV sterilizers are very particular in terms of the required flow rates and having that direct flow control means you can tune the UV sterilizer flow rate according to the particular algae, bacteria, or protozoa you're trying to target.  

Things To Consider When Choosing the Right DC Pump

  • What is the purpose of the pump?
  • How many GPH do you need? 
  • Size of the plumbing connections?
  • PVC or Flexible Tubing?
  • Safety features

The vast majority of new DC Pump users are looking to replace their old AC return pump with a fancy controllable DC return pump. This means you need to choose the right size pump to accommodate your tank's ideal flow and then also ensure the pump can easily integrate into your existing plumbing. The size of the plumbing connections and the type of connections will matter. 

All DC pumps are controllable but some of the more advanced DC pumps have some built-in safety features you should consider. Overheat protection or integration with a float valve are the most common ways DC pumps avoid a dry run situation. In either case, the sensor or switch will tell the pump to shut down if the pump is left to run dry.  DC pumps with wireless control capabilities will give you control via an app on your smartphone and often have the ability to send push notifications when something goes wrong. If these protections are important to you, be sure to choose a pump that meets those standards. 

BRS Recommended DC Return Pumps