Advantages of a DC skimmer?

[Sierra_Bravo]

Do I really need a DC skimmer? Is there really much of an advantage in using a skimmer with a DC pump as opposed to AC? I would imagine there may be some energy savings, but is the speed control really all that big of a deal? What other advantages are there?

I'm eyeing purchasing a larger skimmer, especially with Black Friday approaching. I have been looking at Skimz, Reef Octo, and Bubble Magus primarily, and all three have a DC option in the size range I need (actual water volume around 130g, light/med bio load now but that will be changing).

I'm just not sure what the DC option gives me.

 

[Breadman03]

There may be a little energy savings, but I think the main difference is vibration. DC pumps tend to run more quietly than AC.

 

[kinetic]

There may be a little energy savings, but I think the main difference is vibration. DC pumps tend to run more quietly than AC.

In theory yes, but I tried a Simplicity 120 DC and the pump itself is silent, but once you put air into the mix, the load on it makes the pump very loud. I ran it side by side with a NYOS Quantum 120 which has an AC pump, and the NYOS was quieter. Kind of strange. I tried two brand new Simplicity pumps and swapped out impellers as well. So overall, I think DC pumps are quieter, but when they started cutting up air it got prohibitively loud. It could've just been my Simplicity skimmer sound.

I think Skimz uses the same pump (both Jebao rebranded).

Reef Octo, however, uses the Reef Octopus VarioS pumps! I wish they had one that would be small enough for my tank. My return is a VarioS-4 and it is so silent, doesn't even register a decibel above ambient.

 

[Shigshwa]

I find that the whirring motor-like noise of a DC pump is more tolerable than the hum produced by an AC pump. It's less noticeable for me.

Otherwise, in terms of performance, I suppose the speed control makes it easier to set the wetness of the skim.

 

[kinetic]

I find that the whirring motor-like noise of a DC pump is more tolerable than the hum produced by an AC pump. It's less noticeable for me.

Otherwise, in terms of performance, I suppose the speed control makes it easier to set the wetness of the skim.

Yeah the sound is very different. It’s subjective for sure.

One thing I noticed, the DC pump had weird occelations and the water level would constantly surge. Simplicity said the power was not as even? That’s why it surges. Seemed weird but both of the pumps showed the same thing. Could just be the jebao pumps though!

 

[Shigshwa]

Yeah the sound is very different. It’s subjective for sure.

One thing I noticed, the DC pump had weird occelations and the water level would constantly surge. Simplicity said the power was not as even? That’s why it surges. Seemed weird but both of the pumps showed the same thing. Could just be the jebao pumps though!

Strange, I have a Jebao running my skimmer, and I don't have that problem. I think it could be a faulty pump.

 

[kinetic]

Strange, I have a Jebao running my skimmer, and I don't have that problem. I think it could be a faulty pump.

That's what I asked, but they shipped me a brand new pump to try just in case. Same deal.

 

[Sierra_Bravo]

If sound is the main concern than I'm fine sticking with an AC pump. I was curious if the variable speed provided a level of tuning that may be significant.

Marine Depot has a good sale on Bubble Magus currently. I have an undersized Curve 5 now; I may move to the Curve 7 if a DC pump isn't a big deal.

 

[Mrx7899]

My skimz DC skimmer is silent doesn't make any noise DC's nice because you can adjust the skimmer bubble height with the pump instead of adjusting the valve makes it easier to tune

 

[amps]

I've got a Cloud 9 skimmer with a Jebao DC pump. I love being able to tune it down using the controller without having to adjust the pipe. I tend to use the pipe for very subtle adjustments but when I make changes to the tank that will result in overskimming (epoxy in some rocks/frags, add some coral food, etc..) I can just turn down the pump to 50% without ruining the perfect pipe tuning.

 

[kinetic]

If sound is the main concern than I'm fine sticking with an AC pump. I was curious if the variable speed provided a level of tuning that may be significant.

Marine Depot has a good sale on Bubble Magus currently. I have an undersized Curve 5 now; I may move to the Curve 7 if a DC pump isn't a big deal.

Ultimately, you just set the skimmer to something that works and never need to touch it again. I found that the skimmer body is really setup to be run with the pump at full strength, and the main adjustments are still the wedge/air. The "steps" on the DC controllers are pretty big, and so fine tuning that way just doesn't work well. Using small adjustments to the wedge pipe is still much better for fine tuning.

However. You could get a VMD module for an Apex, and connect a Reef Octopus VarioS pump that's in the RO skimmers, to it, and do 1% pump power changes. That would be the only time I think a DC would be better for tuning than an AC. Again, you'll probably fine tune it a bunch and then really never need to touch it again.

 

[Ferrell]

In theory yes, but I tried a Simplicity 120 DC and the pump itself is silent, but once you put air into the mix, the load on it makes the pump very loud. I ran it side by side with a NYOS Quantum 120 which has an AC pump, and the NYOS was quieter. Kind of strange. I tried two brand new Simplicity pumps and swapped out impellers as well. So overall, I think DC pumps are quieter, but when they started cutting up air it got prohibitively loud. It could've just been my Simplicity skimmer sound.

I think Skimz uses the same pump (both Jebao rebranded).

Reef Octo, however, uses the Reef Octopus VarioS pumps! I wish they had one that would be small enough for my tank. My return is a VarioS-4 and it is so silent, doesn't even register a decibel above ambient.

Just chiming in with my 2 cents, been using the varios to fill my DT from a mixing tank and very pleased with quit running. The skimz dc pulp not as quiet as hoped. Still in the preliminary run cycle so hopefully it will chill out soon. Only went dc for the noise factor as this DT will be in my rather small living area. So far happy with the lack of AC noise

 

[TangingOut]

With the air mixed in, it's definitely not silent. Only advantage for me is feed mode for cleaning out the cup. Then again my last skimmer was on a triplite power strip with individual switches so the difference is a switch vs a button.

 

[roberthu526]

In theory yes, but I tried a Simplicity 120 DC and the pump itself is silent, but once you put air into the mix, the load on it makes the pump very loud. I ran it side by side with a NYOS Quantum 120 which has an AC pump, and the NYOS was quieter. Kind of strange. I tried two brand new Simplicity pumps and swapped out impellers as well. So overall, I think DC pumps are quieter, but when they started cutting up air it got prohibitively loud. It could've just been my Simplicity skimmer sound.

I think Skimz uses the same pump (both Jebao rebranded).

Reef Octo, however, uses the Reef Octopus VarioS pumps! I wish they had one that would be small enough for my tank. My return is a VarioS-4 and it is so silent, doesn't even register a decibel above ambient.

I have the 300 ext with VarioS 6 Pump. The pump itself is indeed silent. The air draw and mixing action is loud however. This is something you can’t really avoid.

 

[acro-ed]

I have two identical skimmers (iTech 400), one with an AC pump and one with a DC. I ran both for a long time, though only running one of them now. I never noticed a difference in noise/hum or electrical consumption. Granted, I wasn't tracking it, but it was entirely inconsequential. I am able to "tune" the DC skimmer without adjusting the water output pipe, but I can accomplish the same thing on the AC one by adjusting the output pipe. I honestly don't think one is better than the other. I haven't put an air meter on the intake to evaluate the air volume, but anecdotally the skimmers perform the same. I wouldn't hesitate to swap them between systems if needed; as a practical matter I would get the same performance.

AC = Askoll/laguna 1500 block with custom acrylic volute (rated at 1500 L/h) (similar to a Bubble King red dragon, but with a nicer volute)
DC = Skimz VSC 10000 (DC Leopard cone skimmer pump) (rated at 1200-2400 L/h)

While the DC pump is theoretically capable of drawing more air, the "ideal" ratio when I set it for optimal performance is not at the "max" setting. The AC pump is already "at" the "ideal" setting because of the manufacturing tolerances of the impeller design and volute dimensions for the speed of the motor.

Truly it's a wash and a matter of personal preference.

The only reason I would recommend the DC over the AC would be if you were in the same situation as I was and an original AC pump went out and you needed to retrofit a new pump without knowing the exact air and water output that would be optimal for your skimmer volume and design. Otherwise, I would choose whichever was cheaper and/or had more readily available parts.

Keep in mind that my experience here is between one of the quietest AC pumps on the market vs. a mid-tier DC pump.

I do believe that the bubble size is slightly larger on the DC pump, but both stack bubbles perfectly up the neck without swirling or "dropping out" which is the sign of a perfectly tuned skimmer. If I crank the DC pump up too high I do get swirling/dropout of bubbles, which is why there IS a perfect "air volume to water volume/velocity ratio" for every skimmer.

As a corollary to the above, I also have a smaller Skimz SK181 skimmer with an AC pump (so about half the size, or less, than the iTech's above). I feel like the pump is reasonably quiet, but is a little louder, IMO, than the Skimz DC pump that is much larger (and also louder than the custom askoll AC pump). I'm dealing with sample sizes of "1", but hopefully this helps.

-Ed

 

[Philip Chin]

yes,very quiet and energy efficient.

 

[mkmreefing]

I've got a Cloud 9 skimmer with a Jebao DC pump. I love being able to tune it down using the controller without having to adjust the pipe. I tend to use the pipe for very subtle adjustments but when I make changes to the tank that will result in overskimming (epoxy in some rocks/frags, add some coral food, etc..) I can just turn down the pump to 50% without ruining the perfect pipe tuning.

What jebao pump are you using trying to convert mine to dc as well