Mr. Saltwater Tank

DC Powered Protein Skimmers: The Next Big Thing, Or The Next Big Fad?

One fun aspect of the saltwater aquarium hobby is that it is constantly evolving. Back when I started my first saltwater tank in the late 1980’s, live rock was virtually unheard of and protein skimmers were all air stone driven and very pricey.

Fast forward to modern day and the latest “breakthrough” in protein skimming has arrived: DC powered protein skimmer pumps.

Before I dive into why I think DC powered skimmer pumps are worth about 10 seconds of your time (at most), you need to understand why these pumps are being touted as the next best thing for protein skimmers.


A DC pump gives you the option of variable speed control which mean you can now control how much water is entering your skimmer via the pump. An AC powered skimmer pump is either on 100% or off and the only way to control flow through the skimmer is by restricting the water leaving the skimmer through the output pipe.

The controllability of these DC pumps often includes a built-in feed timer that will shut off the pump for a number of minutes in anticipation of your sump filling with water. (Unless you are running a recirculating skimmer, a significant rise in water level in your sump can cause your skimmer to overflow).

Finally for controllability, a DC pump also can do a “soft start” 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.

Sounds great right?

Combining the controllability and added efficiency of these DC skimmer pumps, why am I clearly not a fan of them? Because more isn’t always better.

First, I’ll clearly go on record saying that the added efficiency of these pumps is a good thing. Granted that the potential carbon footprint gain is very likely negated by the production and shipping of these pumps, trying to at least reduce the electricity consumption of our tanks can’t hurt.

That being said, one truth when it comes to saltwater tank hobbyists is that we love to fiddle with everything. We will over analyze, tweak, plan and re-plan to the point where some of us never get the tank started. Furthermore, the gains from these tweaks and analyzations are usually negligible at best. This fact is especially true with a DC skimmer pump.

Given that an AC powered skimmer pump is either on 100% on or off, the only gain out of the variable water flow of a DC powered skimmer pump is that you can turn it down.

Do I believe for a moment that if you dial back the setting on the pump that your skimmer will create large amounts of more or better skimmate?


And if a manufacturer knew that less flow through the skimmer meant better skimmate production, don’t you think they’d just use that setting for the pump? Or go with a smaller pump all together? Why would they leave themselves open to a bad customer experience when they could give the customer what they want (good skimmate in an easy to use package) right out of the box?

Furthermore, introducing a variable speed pump into the already existing equation of variable air intake and variable water output from the skimmer, the number of potential combination of settings just went up – way up. 

More combinations means less chance you’ll actually hit the “perfect” combination of air flow, water flow and water output – assuming this perfect combination even exists. Sure you reef junkies will relish the fact that you can spend days of your life trying to find that perfect setting. And I have no doubt that you’ll bask in the glory of announcing to the reef keeping world on your favorite forum that you’ve unlocked the puzzle of the perfect air and flow combination and now your SPS growth has doubled…overnight. For everyone else, you’ll likely try a setting or two, then leave the skimmer on full blast and go on with your life.

But how would you ever know that you hit that perfect combination? I highly doubt a significant increase in skimmate is going to happen by stumbling across the perfect setting. What’s more likely going to happen is that you’ll turn the skimmer pump down too far and skimmate production will drop because there isn’t enough water flow through the skimmer! Just because something is controllable, that doesn’t mean it’s performance will be significantly improved due to the controllability.

From a control standpoint, the feed timer feature of these DC pumps is nice for those of you that don’t have a controller, but I wouldn’t spend any money swapping out the pump on your existing skimmer for a DC pump. Instead, put that money towards the cost of a controller that can control not only the skimmer, but also the rest of your tank.

I will say the soft start feature is nice as impellers for pumps can be pricey and sometimes hard to find. Is the soft start feature important enough to me to want to switch to a DC powered skimmer pump?

No. Mainly because I’ve only ever had to replace 3 skimmer impellers or shafts throughout my whole saltwater career.

Finally, If I was shopping for a new skimmer would I add a DC driven skimmer to my list?

The only reason I’d consider a DC powered skimmer is if I couldn’t find a AC powered skimmer that fit my needs.

I love new toys for my saltwater tank, but I’m not interested in, nor do I recommend you paying much attention to this DC powered protein skimmer fad.

Strike protein skimmers are off your list for where to use a DC powered pump, and add a DC powered pump to this place


Browse the Store! Questions?

Comments for this article (29)

  • Marine MaYHeM says:

    Funny how I remember people saying how LEDs were just a fad, and not to bother wasting money on them, even if they would save you money in the long run. Personally when I’m looking for a new skimmer, I will consider one driven by a DC pump so I can save a little on power usage, an save a lot on not having to replace impeller shafts as often (much like I no longer need to change light bulbs). Also the new waveline dc pumps are apex controllable, which leads to a whole new league of aquarium controllability.

  • paulhr says:

    I think you are missing the point. Being new to the hobby I currently frustrated trying to find a output valve setting that does not fill my skimmer cup with water. I set it, bubble only up the neck, come back a day later only to find the cup full of water. What seem to be happening is that as my sump water level goes down due to evaporation, the pressure on the output pipe changes (the sump water level must be between the top and bottom of the output pipe.) which then causes the bubble level to change in the skimmer. But, if the flow was controlled by the pump it would not matter what my sump water level was, I would get consistent flow through the skimmer.
    Water flow controlled through the pump speed and not the output pipe is a great idea!

  • paulhr…an auto top off system will solve your skimmer issues.

  • Jackie says:

    I have a Reef Octopus POV skimmer with a DC pump. Do I think it was worth it? Yes. This skimmer is a beautiful piece of equipment that does an excellent job – best skimmer I’ve ever had. Of course, the skimmer could work with an AC pump, but the DC does make a difference. For instance, there have been times that I have added things to the tank that make the skimmer go into overdrive. In the past I had to turn the skimmer off till the water normalized. However, this skimmer pump allows me to turn it down to prevent too much wet foam and turn it gradually up over a period of time. Another thing I love is that every now and then, no matter what skimmer it is, it will go nuts and foam away and overflow. I have a waste collection cup with auto shut off to prevent gunk from reentering the sump, but the DC pump also allows me to control the power to prevent this in the first place. The DC pumps aren’t that much more than AC, and after years with AC headaches, they’re worth it.

  • DPB says:

    I have to agree with Jackie on this one. It’s the fine tuning that will make the DC pump a mainstay in the hobby. I agree with Mark that if it isn’t broke, don’t fix it, on an existing set up. BUT, if I am upgrading or starting new, I would definitely spend the little extra for a DC pump to have that fine tuning capability and to run more efficient. It’s really just an evolution of the industry and not so much a fad. Re-read this in 2-3 years!!

  • Jeff says:

    Mark, to your comment to paulhr. An autotop off also adds another element to the equation. While I do think it is an very good component to have it really doesn’t get to the root of the problem. What is needed is a sensor controller in the skimmer so that it can auto adjust the flow rate to maximize the amount of gunk collected. So variable power is a good step along the way.

  • Joseph C. says:

    Would another benefit of a DC pump be easier integration into a battery backup system? I don’t know, just wondering. Maybe in the event of a power failure someone would only be wanting to keep a bare minimum of things running for the longest amount of life support time and a skimmer wouldn’t be one of them. Maybe DC motors could be used in other applications for this reason though?

  • Edward says:

    If you are married the most important benefit to a DC pump is how quiet it is. My mag-5 drove the BOSS nuts..

  • Richard says:

    I have been using a DC powered skimmer the RLSS 10-i since October 2012. I was unsure of it at first but after using it I think it is a bit. More useful for deeper sumps since the speed can be adjusted raising or lowering water levels without having to raise or lower the skimmer to fine tune it. I must say though my pump did die and getting in contact with RLSS to get it fixed or replaced is not easy since they are in Canada. You may get better results trying to call or email the President than getting in contact with them.

  • Jeramy says:

    I believe that these fall in with the sunrise sunset features on lights it is cool but a completely unnecessary complication to our systems. The more you are tweaking and changing your system the less stability you will have and one thing is proven time and again with reef keeping stability is king!

  • Anim8me2 says:

    There is a slight flaw in the logic regarding Co2 footprint and the idea that production and shipping negate savings.
    If AC pump and DC pump cost the same to ship and there is little difference in production costs then the savings to the consumer and lessening of the carbon footprint is NOT negligible especially over a period of years.

    Also, the idea that I might be able to add the DC pump to an aquarium controller down the road opens up a lot off possibilities for me when doing things like water changes, dosing with additives that effect skimmer output and myriad other operations that effect skimmer operation. A touch of a single button to set things up correctly sounds like a win to me.

  • kevin says:

    I see one advantage of this.

    If you know you’ll get a bigger tank you can get a big skimmer on 50%. And still have a good reason to get a bigger tank :).

  • Tyler D says:

    Right Mark, why oversize a protein skimmer only to turn it down. That’s like buying a Ferrari and driving like a grandma. Spending extra money for less power is about as pointless as cooking yourself a whole turkey and eating only a leg.
    Dc pumps themselves are outstanding. They can make waves, your return pump could have a night setting and even a random flow. Another cool use is when using them for water changes…sometimes the initial burst that comes out of the hose will splash…wouldn’t it be nice to slowly come on and gently fill the tank? And above all, you can oversize just incase and when it ends up being too much gph you can set it lower and the electric bill won’t be quite as bad. You can use that extra $3 to get something for your tank…like a snail!

  • Henry says:

    But Mark, you forgot to mention that the dc pump is perfect for an off-grid tank!

  • Dennis says:

    Soft start and power-loss is the only reason for the need for a DC pump.
    To play with something just because you can, come on a lot, can happen to our tanks without our help.

  • Tony says:

    I love my Reef Octopus skimmer. For my 75 gallon tank it works well.

  • Preston SD says:

    He is right, the addition of 12V variable DC offers no advantage. In fact there are innumerable drawbacks to 12V motors especially when operated in to the 7V range. Continuous duty 110V are superior in every way if we could get 220V like the rest of the world your skimmer pump would last for years beyond what we are sold in the Americas. The reasoning behind this 12V setup probably has more to due with the fact it cost almost nothing to produce 12V motors and the replacement pumps will be sold on a yearly basis. I have Octopus skimmers in three tanks with Sicce pumps they work awesome and I would not switch brands anytime soon, but 12V variable motors? No thanks

  • Craig m says:

    Mark: by all the comments left, sounds like your losing this battle.

  • wing says:

    Every time when you see some item has a huge discount, it is a clue of new generation coming very soon. Like Eshopp Cone skimmer 15% off 2 months ago, Ecoxotic Panorama Pro Led module 15% off beginning at 2 months go, LED Hydra comes one now.

  • Luke says:

    Some good points there. However i place a higher value on lowing power costs. Reason being is not because i’m a planet warrior, but i am a wallet warrior. My power bill has become to costly and to reduce it i was force to shut down the smaller of my 2 tanks. My biggest tank is a 1200L (318 us gal) and here in Australia equipment that is capable of running a tank this big is power hungry or expensive. I recently had to update my Tunze silence 3000 return pump to a wave line DC 5000 pump because it’s low power usage. I have also had to replace my chiller and skimmer for the same reason. In the end i have learnt the hard way. Plan your equipment for long term costs. better to have lower running costs. saves time, saves money.

  • Kevin J says:

    After having 2 dc pumps die on me, I have never looked back when I purchased my Reefflo. Also, I don’t see those pumps running off batteries, they plug into a wall outlet and convert 110 to 12 volts. Hmmmm how much electricity is turned into heat (wasted energy) by the conversion? There are both good and bad points to them. Really, how many of us tweek our skimmer daily? We set it and forget it, and re-adjust it after cleaning. Ok, I will give in on the return side of this debate. But when that little controller box dies be ready replumb in a new pump. So far they have proven unreliable to me.

  • steve ford says:

    Just want to say that AC pumps or motors can be controlled just as easy as DC pumps in fact they can be controlled better.
    Im an electrician and I’m using these all the time.
    I love the hobby new technology comes out all the time, the flexibility the these pumps give is better than a straight plug in the wall unit.
    How long they last in a system will depend on quality .
    I think they are a great addition to our hobby

  • Jason says:

    #1 reason for a DC skimmer: my tank is in my living room, and I like it quiet in there. DC pumps are significantly quieter.

    Mark, just because you _can_ control something doesn’t mean you have to. I expect that when I set my new tank up, I’ll be getting a DC skimmer. I’ll peg it at 100% and control it from my Apex with two settings – “on” and “off”. I don’t really care about the controllability. I care about the noise and the lower power requirement.

  • Jason…I’m not sure what AC pumps you’ve run as some can be quite loud such as the Mag-Drive pumps. More quality pumps like the water blasters and Red Dragon pumps are completely silent.

  • Allen says:


    I just purchased a Reef octopus DC150. Being cheap like me, the 8 outlets on my apex power 8 are like gold. The 10 second delay on start up allows me to run both the main pump and skimmer on a power strip plugged into a single socket because the 10 seconds gives mt main pump time to drop the water level in the sump which prevents flooding. Also i dont believe ac pumps are particularly adapt at frequent stops and starts and i do 2-3 feedings a day. Lastly the ability to turn down the pump is coming in handy this first week as i dont have mt sump stand set up yet and having it in 9.5 inches of water instead of the recommended 6.5 to 7 inches floods it which would render it unudable. I suspect i will find this feature handy in overfoam scenarious that would ordinarily require a complete skimmer shut down (food/materials in the tank like epoxy). Would i rush out and buy one? No. But i was buying one anyway and ill never be withour one going forward. No to switch my main pump to DC (ill use the old one as an emergency back up)

  • Cali9dub says:

    I would assume that the variable control of the DC pump would indeed produce more skimmate at a lower setting. Of course that would depend on the height of the water in your sump. So instead of trying to use stands to raise/lower your skimmer physically to accommodate a static flow pump, you can now adjust the flow of the pump based on the water level of your sump. Since there are so many variables in the constructions of sumps I believe the variable speed pump is definitely a plus to dialing it in as opposed to rigging the skimmer. Obviously the performance of a skimmer is based on an air flow to water flow ratio. Water height in the sump is a huge variable with a static speed pump. My 2 cents…

  • James says:

    The benefits of a DC pump are:

    Higher RPM because no alternating current used.
    Less current = cooler running.
    Safer to a degree with much less voltage.
    DC pumps generally run quieter because no AC hum is produced.
    Would I ever reduce pump speed in a skimmer, unlikely.

  • Sunny says:

    Hi Mark,

    Can I ask if you have any thoughts on this topic now as it has been so long?

    I am getting a controller so the main reason I would get a DC Skimmer is the noise. Or do you think better value is in spending the same amount of money and getting a higher quality skimmer or saving the extra money?

    My tank is going in my sons bedroom so noise is a concern so I could always not run the skimmer at night. Also I am going to stock the 120G extremely slowly so would you recommend a quality AC skimmer that is rated for a 120G heavily stocked tank and simply not run it at night if it is too noisy? I was also going to run the airline outside so that’s another factor because if I don’t run it at night the pH may not be as stable.

    Thanks so much 😉

  • John says:

    Dc pumps are great when they work but the extra level of complexity in design means they are more prone to failure. Equipment failure is one of the big reasons people loose their livestock.

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.