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View Full Version : ReeFlo Hammerhead mod?


azrednex
02/25/2008, 07:10 PM
We have a ReeFlo Hammerhead we are planning on using when we set up our 360 gallon peninsula tank. We just obtained a 120 gallon to use in the interim. Is it possible to mod the Hammerhead down to run the closed loop in the 120?
Thanks,
Mrs. azrednex

BeanAnimal
02/25/2008, 07:42 PM
You can throttle the pump back with a valve on the output without any problem or damage to the pump. It will also draw less current when it is throttled back. DO NOT restrict the input side, only the output side.

hahnmeister
02/25/2008, 09:28 PM
It MIGHT draw less... it MIGHT draw more than 350watts. As you restrict it, the wattage rises up to almost 400 watts until you can create more than the equal of about 18 feet of head pressure.

I know someone with two Hammerheads on his 210g. Its not a big deal. The thing about gph ratings is that its all in how you use it. My uncle is into seahorses/pipefish/etc... so he has a gentle tank, but he uses a 1000gph pump on a 40g! The thing is, he uses a couple full length spraybars at the front and back of the tank to spread out the flow across the whole tank.

Just like you can use certain methods (nozzles, eductive flow/gyre tank, etc) to make tons of flow in a 120g with nothing but a 1000gph pump, you can do the equal and opposite to make 5800gph seem like very little.

By using spraybars, or multiple outlets on a manifold, you can break up the pump's flow into multiple smaller outlets. Just by breaking the flow up into 10 smaller nozzles, say 3/4" in diameter, you will have 580gph from each outlet... whoopie. Then, if you aim many of these at each other, they will cancel each other out a bunch.

I cant say exactly what will work for you, but using that general idea, Im sure you can figure something out.

Im thinking one spray bar along the top front edge of the tank and one along the back... both about 1.5" in diameter, and both with 10 1" holes facing across the top of the tank would be good (if you can hide it enough). You could use an Oceans Motions to switch the flow between the front and back spraybar and get a nice overall effect. Something like that...

BeanAnimal
02/25/2008, 09:37 PM
Hahn, can you elaborate on your statement?

As you increase the effective head, you reduce the output of the pump. This reduces the work that the pump does and therefore the power that the pump uses.

If you look at a pump curve, you will see as flow decreases, so does power consumption :) This is true for anything over about 3.5 feet of head for the hammerhead. I think I see your mistake... You can't read the pump curve by follow the head pressure over until it intersects the power curve.

http://www.f3images.com/IMD/MD_images/aquarium/pump_mdm_sequence_reeflo_hammerheadcurve.jpg

Thoughts?

cweder
02/25/2008, 10:28 PM
I would say using what Bean and Hahn suggested would work. I adjust my Barracuda return this way from heavy current to very gentle depending how I branch out the flow using loc-line and ball valves. Branching out the loc-line a few times really calms thing down fast.

just dave
02/25/2008, 10:44 PM
<a href=showthread.php?s=&postid=11942583#post11942583 target=_blank>Originally posted</a> by BeanAnimal
Hahn, can you elaborate on your statement?

As you increase the effective head, you reduce the output of the pump. This reduces the work that the pump does and therefore the power that the pump uses.

If you look at a pump curve, you will see as flow decreases, so does power consumption :) This is true for anything over about 3.5 feet of head for the hammerhead. I think I see your mistake... You can't read the pump curve by follow the head pressure over until it intersects the power curve.

http://www.f3images.com/IMD/MD_images/aquarium/pump_mdm_sequence_reeflo_hammerheadcurve.jpg

Thoughts?



Let me see if I have this right. At 0' the pump is putting out 6000gph and drawing 350 watts. At 12' it is about 4400gph with a draw of about 387 watts. 16' its 3600gph with a draw of about 375 watts and so on. Is that correct?

hahnmeister
02/26/2008, 01:56 AM
"you will see as flow decreases, so does power consumption"

Er, no it doesnt. You see that dotted red line as it makes a peak at about 4700gph/10'/390watts, right?

Bean, I know the assumption is less flow = lower wattage, but no mistake on my part :) (I read it with a vertical line BTW). Not all motors decrease RMS wattage as you increase resistance, and this isnt always proportional to the perceived work being done either. As you throttle the pump back, if you read the dotted red line it shows that the wattage does increase to about 390watts at about 4700 gph. This is known to be true of many of the ReefFlo pumps, including the dart I have. The wattage at 5800gph is lower than the wattage at 4800gph. Not that I see this situation as pure translation between wattage and pump (it might be, but Im not interested enough to find out), but maybe pumping 5800gph a height of 0' is easier than 4700gph to 10'? Otherwise seems the pumps dont 'slow down' from restriction until you hit about 4700gph/390watts/10' of back pressure... they just do more work. I have observed the same with many Iwaki pumps as well, so I would assume it is true of many shaft/air cooled external pumps.

hahnmeister
02/26/2008, 02:09 AM
<a href=showthread.php?s=&postid=11943325#post11943325 target=_blank>Originally posted</a> by just dave
Let me see if I have this right. At 0' the pump is putting out 6000gph and drawing 350 watts. At 12' it is about 4400gph with a draw of about 387 watts. 16' its 3600gph with a draw of about 375 watts and so on. Is that correct?

Yes, you and I are reading it right, Bean needs to take another look. Yes, the pump does increase its wattage draw. To make it worth restricting, you would have to restrict it down to 3000gph or more. Thats why I wouldnt suggest restricting it, but rather running it through more outlets/diffusers.

gopack's Hammerhead was about 360 watts when hooked up on a recirc loop, but when changed out to a return pump for his 320g and multiple frag tanks, it jumped to just over 400 watts. Trust me, Hammerheads are on every large tank in our reef club it seems.

Compguy
02/26/2008, 06:19 AM
I love my Hammerhead pump, you would be surprised to hear that I run it on my 55g, but just after the pump is a valve and probably runs about 60-70% open, plus I have about a 10' head height from the basement to the tank and up at the tank it is split into three 3/4" outlets, two of the outlets run on a SCWD and those decrease flow quite a bit and the other is on a 3/4" Sea Swirl, I am hoping that this will work good enough to create flow in the tank.

I did read in the Hammerhead manual and I quote as I am looking at it right now
"ALL OF OUR PUMPS CAN BE "VALVED BACK" AS LONG AS ITS DONE ON THE DISCHARGE LINE. IT WILL NOT ONLY REDUCE THE FLOW, IT WILL LOWER THE WATT USAGE AND EXTEND THE LIFE OF THE MOTOR AND THE SEAL!"

of course may not be true with the wattage in all applications, but no harm if you use a valve on the output side to reduce the gph.

BeanAnimal
02/26/2008, 07:40 AM
NO need to take another look hahn, I can read a pump curve. :) We are just looking at different parts of the curve and applying slightly different reasoning to the application.

<a href=showthread.php?s=&postid=11944325#post11944325 target=_blank>Originally posted</a> by hahnmeister
"you will see as flow decreases, so does power consumption"

Er, no it doesnt. You see that dotted red line as it makes a peak at about 4700gph/10'/390watts, right? Er, yes it does for almost the entire pump curve :) I am speaking about everthing left of about 8' of head... where most of us would be running, most of the time.

if you read the dotted red line it shows that the wattage does increase to about 390watts at about 4700 gph. This is known to be true of many of the ReefFlo pumps, Not just reeflo pumps, but many pumps of similar design. Yes at the very top end of the output there is a slight reduction in wattage from the 9' head point to the 0' head point. There is no such thing as pumping at 0' head. Even a minimal piping system will add a few feet of head.

So yes, the pump curve above does show in increase in wattage between 0' of head and 9' of head. From 9' to shut off, the wattage decreases.

In real world usage valving back such a pump will, in most cases reduce the power consumption of the pump.

Lets take the graph at face value
00' - 6000 GPH - 360 Watts
04' - 5500 GPH - 370 Watts
08' - 5000 GPH - 375 Watts
12' - 4300 GPH - 370 Watts
16' - 3600 GPH - 360 Watts
20' - 2400 GPH - 325 Watts
24' - 0000 GPH - 200 Watts

To make it worth restricting, you would have to restrict it down to 3000gph or more. Thats why I wouldnt suggest restricting it, but rather running it through more outlets/diffusers. Please, lets not confuse the issue here. The point was that he could valve back the pump, not at what point he could start banking savings. If his piping system has 6' of total head, then valving back from 5200 GPH to 4000 GPH would show a reduction in wattage. This is beside the point.

The entire premise of the post was to let the OP know that it was safe to valve back the pump.

SDguy
02/26/2008, 11:36 AM
Yuck! So my CL calculates out to about 6' head...so not only am I getting less flow, but I'm using even more watts? That blows.

hahnmeister
02/26/2008, 12:59 PM
Bean, he would have to back it down to lower than 3000gph to see a reduction in wattage, but if he let it run free flow on a closed loop, Im sure he could keep the head well under 6'. And in the case of a closed loop, I dont see most people hitting that point, which is more like 18 feet of head before you start dropping below 350 watts. Many people I know have their Hammerheads close to 400 watts if used as a return, but lower if used as a closed loop.

BeanAnimal
02/26/2008, 04:16 PM
If it pleases you to look at it that way, then yes. I covered that in my last post (you appear to have ignored it). No big deal... this is kind of silly and there is no need to argue about the semantics of something so straightforward.

The closed loop will certainly have several feet of head on it though and I think that is being missed here. Where there is pipe, there is friction. Where there are nozzles and fittings, there is friction. Friction (and turbulance) equate to head.

Anyway, the POINT (again) was that the pump can safely be valved down. Doing so CAN also reduce the power consumption of the pump and WILL lengthen the service life of the pump.

Enjoy...

Bean

nyvp
02/26/2008, 06:18 PM
you would have been better off with 2 darts for more flow and less wattage with the added redundancy. the hammerhead and barracuda don't measure up to dual darts unless you have a lot of headpressure .

BeanAnimal
02/26/2008, 06:34 PM
Never looked at the curves that close

Here is the Dart, followed by the Hammerhead

http://www.saltycritter.com/images/pics/sequence/sequence-reefflo-dart-curve.jpg
http://www.saltycritter.com/images/pics/sequence/sequence-reefflo-hammerhead-curve.jpg

BeanAnimal
02/26/2008, 06:48 PM
Lets take 2', 4', 8' and 10' of head.

at 2' the dart flows 3300 GPH at 150 Watts or 22 Gallons a Watt
at 2' the barracuda flows 5700 GPH at 365 Watts or 15.6 Gallons a Watt

at 4' the dart flows 2800 GPH at 158 Watts or 17.7 Gallons a Watt
at 4' the barracuda flows 5500 GPH at 375 Watts or 14.6 Gallons a Watt

At 8' the dart flows 1800 GPH at 155 Watts or 11.6 gallons per Watt
At 8' the barracuda flows 5000 GPH at 375 Watts 13.3 gallons per Watt

At 10' the dart flows 1200 GPH at 145 Watts 8.3 gallons per Watt
At 10' the barracuda flows 4600 GPH at 380 Watts 12.1 gallons per Watt

So yeah it looks like at low heads (2) darts may slightly outperform 1 barracuda in terms of overall efficiency. There will be less flow but it will be slightly more efficient. Once you get to about 8' of head, it gets lopsided rather quickly.

Pump curves are always a good thing to look at when choosing pumps!

hahnmeister
02/26/2008, 07:58 PM
I suppose it comes down to if this is a return pump, or a closed loop pump. IMO, keeping the back pressure, esp if a diffuser system is used and decent size piping, under 6' should be easy.

edit: just checked; as long as 2" pipe is used for the inlet/outlet before splitting the output into smaller piping (say dual 1.5" or quad 1", etc) the head pressure will be under 5', close to 4' actually.

BeanAnimal
02/26/2008, 08:18 PM
I have a snapper coming this week. I had planned on putting the meter on it and seeing what it does anway. If I get around to it, i will post the results.

Hahn, on a side note... I gotta get something done about this skimmer pump Every moment with this OR is like being at the dentist when I could be at the bar.