Pump Specs

[chatyak]

I know for reefs your total water volume should be 5 to 7 times the tank's volume per hour.

So I'm planning on getting:

LifeReef Overflow Rated (up to) 700gph

Danner Mag-Drive 500gph as a return pump
Is this return pump any good?
http://www.jlaquatics.com/phpstore/store_pages/details/pumps.php?product_ID=wp-mag05

I'm only going on what I have read lots of people use... seems to be mag drives... what is their website anyway?


Also... what does this mean? The amount it can push based on how far down under the tank it is... 0 feet... 4 feet.... 6 feet?


Flow Rate at 0' Head: 500 GPH
Flow Rate at 4' Head: 310 GPH
Flow Rate at 6' Head: 190 GPH


So if this pump was in my sump technically it would be about 3 feet below it.... so it would be around 320 GPH which is roughly 6 times the total amount needed for my 55 gallon?

 

[der_wille_zur_macht]

"Head loss" or flow at a given "head" is basically a way to measure two things in one simple number: 1) The vertical height a pump is working against (obviously, the higher the height the less flow from a particular pump) and 2) the frictional losses, both from the inner wall of the pipe and from bends, etc in the plumbing design.

Thusly, pumps will be rated for certain flow at a given head. If you know what pump you're using and what head it's pumping against (taking in to account both of the above factors), you can look up on the pump's spec to see how much flow you'll get.

In general, for smallish tanks (say, under 100g) with traditional sumps directly below the tank, you can probably guess about 4 - 6 feet of head loss. If you really want to know, there's a head loss calculator on the RC homepage that'll tell you exactly how much head you'll get from a certain plumbing design.

So, the short version is that the pump you've listed will likely push around 300 GPH in your situation. That's fine for turnover through a sump on a 55 gallon tank, though the next step up in the Mag line (the mag 7 I think?) would give you a bit more oomph.

In general, it's probably safe to say that people aim for about 5x turnover through the sump, but you will definitely need more total turnover in your display tank. Depending on your livestock plans, you might want to shoot for 15 - 20x as a minimum, which means you'll need a few powerheads in there, or a closed loop in addition to the sump return.

 

[Southern Boy]

Head pressure is the heighth your traveling up.So if you have a 3' stand and a 12" tall tank and your pump is say in your sump all the way at the bottom then you have a 4' head.It saying you will only get 310 GPH out of that pump at that heighth.I have been using mags for a while but am starting to steer away from them.The larger ones tend to be noisy and they produce heat.I just changed my mag 12 to a quiet one 5000 on my closed loop and got a 2.5 degree decrease in temp.And that is a dry pump!It's not submerged.It also draws 10 watts less put out 1330 gph with no head loss and is quieter.Also remember to get the specs above out of these pumps you have to pipe it according to the manufacturers suggested pipe size.What size tank is it your wanting to run this on and how big is your sump area?

 

[Southern Boy]

Sorry double post and I see you have the tank size at the bottom

 

[Southern Boy]

As Der wille said a mag 7 will give you a little more oomph.I still have a 7 running my return on my 54 bow front and it does well.I had a 9.5 but it was moving to much water and creating to many micro bubbles.

 

[chatyak]

Ok well I have a 55 gallon tank... I am building a stand that sits at 36 inches... so 3 feet... and the tank is 21 inches high... add a U -tube director for the return so let's say 22 inches plus 36 inches.

This gives us 58 inches of head room from where the pump is for example. So let's say my return pump is going to have about 5 feet of headway.

In order to get (15x the flow??? that sin't going to kill the fish is it lol) I would need a pump rated around 825gph?

Or is my total water volume per hour tallied up between all of the powerheads AND the return pump.

Anotherwords...

Is my total water flow per hour calculated on just the powerheads added up together.... or between the powerheads and the return pump.

Example)

750gph needed.

3 powerheads at 250gph each
Plus return pump

Or...


2 powerheads at 200gph
1 return pump at 500gph

 

[Southern Boy]

Is it going to be a reef tank or fish?

 

[chatyak]

Reef

 

[der_wille_zur_macht]

The "total water turnover" goal of 15 - 20x tank volume per hour includes anything that makes water movement in the display tank. In your case, sounds like that will be the return pump and a few powerheads. You do NOT want to set the return up to meet that goal on its own, for several reasons - you'll have a noisy sump that'll blow microbubbles into the tank, and your overflow probably can't handle that much water anyways.

And no, that much won't disturb your fish. Consider that on a natural reef, there may be many times that much water motion. People with bare bottom SPS-dedicated tanks might be aiming for 50 - 80x tank volume per hour. 20x in your tank won't be overkill, and even at that much flow you might find you have trouble avoiding dead spots.

At any rate, the exact amount of flow is kind of meaningless, it's more important to be concerned about the type of flow in your tank. Generally, you want good, gentle water movement everywhere in the tank. With conventional powerheads and pumps, this is hard to obtain, since they tend to create narrow beams of flow across the tank at high velocity, leaving the rest of the tank motionless. Hence, be careful with how you aim your powerheads and sump return - try to create intersecting flow patterns for instance, where powerheads are aimed at eachother or at the tank walls to distribute the water motion to a larger portion of the tank.

Another alternative is to use the newer "prop style" powerheads. These generally feature a propeller style impeller and a large, open design. They create very gentle water movement, but distributed across a large swath instead of a concentrated beam. Examples of these include the Vortech or Tunze pumps (expensive but high quality) or the new Hydor or Seio pumps.

 

[chatyak]

Thanks for that willie

Does it matter than which type of return pump I get... be it 400gph or 500gph then.... if I am just worried about the total volume per hour... and not the return pumps? Or should the return pumps be the majority of it?

 

[chatyak]

Also... since 55 X 15 is more than my original overflow pick of 700gph... do I need to get the overflow which can handle 1400 gph?

 

[der_wille_zur_macht]

The overflow only needs to be able to handle the total flow through your sump, which will be equal to the flow being pushed by your return pump. So if you stick with a return pump in the 300 - 600 gph range, you will be totally fine with your current overflow setup.

The return pumps are generally not the majority of your overall turnover. In your situation, if you end up with a 300 - 500 gph flow through your sump, you'll probably want about 1,000 gph of flow from powerheads. Ideally, you could get that from two of the smaller Hydor Koralia powerheads, or a few Maxi-jet powerheads if you don't want to spend on the hydors.

 

[chatyak]

Like 2 of these?
http://www.jlaquatics.com/phpstore/store_pages/details/pumps.php?product_ID=hy-kor02

 

[fishb8]

I'd use a MAG 9.5 or similar