Are DC pumps worth the extra $

[McGene]

I noticed that Tunze has introduced a revised 9004 skimmer. The newer one comes with a DC pump and an attachment to turn off the skimmer for a period of time while the collection cup is being emptied and cleaned.

Question: Is a DC pump significantly better than an AC one? The added cost for the "new and improved" version is about $50. I don't need the switch option -- I have easy access to my power bar. Just not sure if going DC is worth the extra money.

Thanks for your comments.

 

[Lloyd Williams]

I know dc pumps don’t start and stop as hard as ac ones do

 

[gcarroll]

I have the DC 9004 and am very happy I went with it. It is just so easy to tune in.

 

[Roid Reefs]

So your DC pump usually is going to save you money on electricity. As well as what LLoyd is saying about easier start and stop. Most are able to change speed of the pump to adjust amount of skimming that is done.

 

[gcarroll]

So your DC pump usually is going to save you money on electricity. As well as what LLoyd is saying about easier start and stop. Most are able to change speed of the pump to adjust amount of skimming that is done.

With both pumps rated at 4w, even if turned down, the DC savings are minimal. Like a penny or two per month. For the most part, DC wattage savings are overhyped.

 

[Mebbid]

From my understanding controllability and silence are what make dc pumps superior. As far as reliability, that remains to be seen. It would probably be a good idea to go with a pump that has proven reliability such as the reef octopus varios model.

 

[Sailingeric]

I have the reef octopus varios model and I like it. It is quiet, it has 5 speeds so I could really dial in my overflow and I like how it has the auto shut off float so should something happen with my overflow it is not pumping my sumps water volume out on the floor.

 

[gcarroll]

From my understanding controllability and silence are what make dc pumps superior. As far as reliability, that remains to be seen. It would probably be a good idea to go with a pump that has proven reliability such as the reef octopus varios model.

Tunze has been making DC pumps since before Reef Octopus was even a company. Reliability is proven when it comes to this and every other Tunze DC pump!!!

 

[WVNed]

All I want my pump to do is pump it's rated flow. So I buy AC pumps. Tuning my overflow takes tiny adjustments on a valve. I don't think 5 or even 10 speed settings is going to do anything for me.

 

[gcarroll]

All I want my pump to do is pump it's rated flow. So I buy AC pumps. Tuning my overflow takes tiny adjustments on a valve. I don't think 5 or even 10 speed settings is going to do anything for me.

We are not talking about DC return pumps.

This thread is in regards to the Tunze 9004 DC skimmer. It has absolutely nothing to do with the Chinese DC pumps out there. The Tunze DC pumps don't have set speeds. They are infinitely adjustable.

 

[WVNed]

We are not talking about DC return pumps.

This thread is in regards to the Tunze 9004 DC skimmer. It has absolutely nothing to do with the Chinese DC pumps out there. The Tunze DC pumps don't have set speeds. They are infinitely adjustable.

LOL

OK but the same thought applies. Why would a correctly designed skimmer need a variable DC pump. I love what the new wave makers and flow pumps can do for my tank but in
many cases a DC pump makes no sense to me.

 

[msl5078]

I'm using one on my new tank build (Varios 2), pairing it with a Sicce pump. Wanted to try the two smaller pumps vs. one huge one this time around and thought why not try the DC pump thing at the same time.

 

[gcarroll]

LOL

OK but the same thought applies. Why would a correctly designed skimmer need a variable DC pump. I love what the new wave makers and flow pumps can do for my tank but in
many cases a DC pump makes no sense to me.

Correct, it does not need a DC pump. It just makes for easy tuning of a skimmer like the 9004. Unlike other skimmers, on the market, this has a very unique design which makes it for a wide range of adjustment possible. If you have never used one, you might not understand.

 

[McGene]

Thanks for all the comments. I'm still doing my research on a suitable skimmer for my JBJ 45. I've read some comments that it's a pretty tight fit and may not perform as well as in a larger space. That said -- the issue my not be DC vs AC pump -- but rather how well it performs in my tank.

Again, I appreciate all the dialogue.

 

[JAMSOURY]

Are DC’s more quieter as well?

How quiet is the tunze 9004? Looking for a good skimmer option for in my room

 

[Roid Reefs]

DC vs AC
AC is a fixed power usage putting out a fixed amount of flow. to reduce this, you need to restrict the flow putting back pressure on the pump.
Think of a car, engine running at 6000 rpms, want it to go slower? lets add a trailer to it.
DC variable power usage putting out variable amount of flow. to restrict it, you turn it down and save power.
In car terms, car is only running at 2000 rpms to have it go slower.
Will save money on electricity as well as life of the pump.
A octo varios puts out 1050 gph at 40w. a mag 9 puts out 975 gph at 93 watts. Half the power, save half the cost of electricity. Then it will be even less if you fine tune it and run it at a lower setting to dial in the skimmer, or return.

 

[gcarroll]

DC vs AC
AC is a fixed power usage putting out a fixed amount of flow. to reduce this, you need to restrict the flow putting back pressure on the pump.
Think of a car, engine running at 6000 rpms, want it to go slower? lets add a trailer to it.
DC variable power usage putting out variable amount of flow. to restrict it, you turn it down and save power.
In car terms, car is only running at 2000 rpms to have it go slower.
Will save money on electricity as well as life of the pump.

Nope, this is a wrong analogy. As you add pressure on an AC pump, it in turn uses less power as it is doing less work.

 

[gcarroll]

A octo varios puts out 1050 gph at 40w. a mag 9 puts out 975 gph at 93 watts. Half the power, save half the cost of electricity. Then it will be even less if you fine tune it and run it at a lower setting to dial in the skimmer, or return.

This only holds true in an environment of 0' of head pressure.

 

[Javamahn]

Nope, this is a wrong analogy. As you add pressure on an AC pump, it in turn uses less power as it is doing less work.

I am revising this post as I would agree that a DC pump on a skimmer is useless except for the noise. On a return pump I using nothing but controllable DC

 

[gcarroll]

I wouldn't say its incorrect. It is another way. Certainly not the most efficient way however, in that instance, the pump is doing more work (moving more water), therefore using more electricity. so with that technique you previous analogy would be correct.

You can ball valve down a pump to a point (typically to 50%). if you need to go lower than 50%, i would recommend the T method. An AC pump works harder and consumes more energy at 0' of head than it does if it is under a load (say 10' or so).