Return pumps come in two flavors, dictated by the electricity that runs them. AC return pumps run on alternating or “AC” power while DC return pumps run on direct current or “DC” power.
AC pumps have been powering our tanks for a long time with a good track record so why fix something that isn’t broken? There are a couple of reasons why these DC pumps are marketed as “better” than their AC counter parts:
A DC return pump gives you the option of variable speed control which means you can now control how much water flows out of the pump. Contract this feature with an AC powered skimmer pump that is either on 100% or off.
This control comes in handy in a return pump as if the flow rate is too much, simply turn the pump down. Need more flow back into your tank? Crank the pump up! Remember that you’ll still need to know approximately what flow rate you need as if you need flow that is beyond the capabilities of the pump given your head pressure, you’re out of luck.
Flow control is achieved through an included controller where flow can be dialed up or down. These controllers often include a built-in feed timer that will shut off the pump for a number of minutes while you feed your fish.
Finally for controllability, DC pumps have a “soft start” feature meaning the pump starts at a low rpm and ramps up to full speed, potentially reducing broken impellers.
DC pumps are more efficient than AC pumps. In other words, it takes less electricity to get more performance out of the pump. That means a smaller electric bill. (I highly doubt that you’ll see a drop in your home power bill if you switch to a DC return pump, but hey, it makes for a great selling point!).
While these DC return pumps look promising, I’ve avoided them for one big reason: quality.
I’ve talked to several saltwater equipment retailers that tell me that they have stacks of dead DC return pumps. I’ve also talked to several other professional saltwater tank installers who have had multiple failures of these pumps.
For the pumps that are still operating, I’ve run across countless stories of the controller for the pump being hot to touch including one instance where the client called the service company to complain about the heat of the box!
I like the concept of a DC-driven return pump and I’m still avoiding them until I see a DC return pump of real quality.Browse the Store! Questions?