Return Pump suggestions....

[whowadat]

Hello,

I've recently put together a sump/fuge out of a 20 gallon long glass tank. Tank water is supplied by a Lifereef HOB overflow rated at 700 GPH average and I have to pump the water back into the tank 4' up. (head) I'll be using a pretty much straight shot of flex hose into the sump, and the system is being used on a 40G breeder aquarium.

I've looked at three pumps for the return.....

MAG 9.5 rated @ 800 gph at a 4' head w/ 90 + watts of power

RIO 14HF rated @ 660 gph at 4' w/ 45 watts of power used.
(RIO 17HF 840 @ 4' w/ 55 Watts)

LIFEGARD Quiet One 3000 rated 700 gph @ 3' with a max head 4'
(rumored to only use 13 watts but that may be a typo - another site has it at using 40 watts)

LIFEGARD 4000 is rated around 1000 @ 3' and uses 50 watts


I'm concerned about heat on such a small setup so less power used seems important, but with the LR overflow sporting a 700 gph "average" that appears to be kind of a 'tweener number when looking at the output of the pumps. I'm also concerned about life expectancy and reliability of the pump - I'd rather pay a little more for quality. Any suggestions and/or other pump(s) I should look into ?


Thanks in advance for any input.

 

[fatboyt123]

what size tank are you putting the water back into?

dont go with the mag nosiey and hot

no rio either as they can also get to hot crack the top and leak oils into your tank killing everything

i would look into an ehiem that will be aroung the power you are looking for like a ehiem 1262

 

[blazin]

I have the same overflow with a 20L long sump. Im using an ocean runner 2500. It doesnt have the flow of the pumps you picked, but I dont really think i need crazy flow thru the sump, i have Koralias in my tank.

 

[whowadat]

40 gallon breeder is the tank.

Good call on the 1262, it looks like 800 gph @ 4'

At 80 watts and 160 bucks its definitely the most expensive to run, sure seems like it would put some heat in the water too at 80 watts.....


I'm not sure I can get away without some sort of valve on the return, looking through Jeff's instructions he basically notes a valve being needed to control the return flow. Ahhhh well, no big deal I guess.....

Thanks for your reply!

 

[TROYREEFER]

I'de go with the mag and if your worried about watts and heat then go with a quite one pumps. I would go with the mag personally because they are more reliable.

 

[whowadat]

Blazin, do you have some sort of valve on the return ?

It's my understanding that the return pump flow needs to match the output of the overflow as close as possible, Jeff notes a valve on the return is probably needed to dial in the input/output of the water. Do you think you're seeing numbers like 700 gph out of that overflow ? That's quite a bit of water being moved around, I would imagine it diminishes after time and the build up of algae and whatnot.....


Thanks for your reply!

 

[whowadat]

Hey Treefer, I like the MAG too. I'm running a MAG 18 on a 120 and I didn't really think they were that noisey, and at 145 watts it doesn't seem to be running hot at all - maybe I'm making too big of a deal out of power use. Aquatictech is selling a quiet one 3000 for 55 bucks so that seems like a reasonable deal, I didn't know the reputation of Lifegard so maybe I'll do a bit more research.

Thanks

 

[blazin]

<a href=showthread.php?s=&postid=15043232#post15043232 target=_blank>Originally posted</a> by whowadat
Blazin, do you have some sort of valve on the return ?

It's my understanding that the return pump flow needs to match the output of the overflow as close as possible, Jeff notes a valve on the return is probably needed to dial in the input/output of the water. Do you think you're seeing numbers like 700 gph out of that overflow ? That's quite a bit of water being moved around, I would imagine it diminishes after time and the build up of algae and whatnot.....


Thanks for your reply!

No valve on the return.

The overflow is only going to take as much water as the return pump will supply. The overflow rate must equal or exceed the pump's return rate. Even though the overflow is 700gph and my Oceanrunner 2500 (@4ft) is probably putting out ~400gph, they are in perfect balance.

A valve is only needed when the pump exceeds the overflow

To accomodate for the slower rate of water, i use a 7/8" U-Tube instead of the 1" that normally comes with the overflow. This prevents bubbles from accumulating in the U-Tube.

 

[One Dumm Hikk]

whowadat, I love my mag pumps. They have survived things that pumps shouldn't be subjected to and they keep running. I had a Mag12 (later a Mag18) on a 90 and never had heat nor noise issues. I would actually have to touch or listen to it closely to even know it was running. Others have different experiences but I have never had noise issues with mine. I had to run a heater in my 90 to keep it at 80 degrees as well so no heat issues. I did keep it around 70 in my house and that makes a big difference as well.

 

[sjm817]

You need ~ 200 GPH minimum to keep bubbles from accumulating in the overflow. With a 40G/20G, I wouldn't want much more than that. If you go for a Mag, a Mag3 or 5 would be fine. The OR2500 is as strong as I would go.

 

[whowadat]

<a href=showthread.php?s=&postid=15043324#post15043324 target=_blank>Originally posted</a> by blazin
No valve on the return.

The overflow is only going to take as much water as the return pump will supply. The overflow rate must equal or exceed the pump's return rate. Even though the overflow is 700gph and my Oceanrunner 2500 (@4ft) is probably putting out ~400gph, they are in perfect balance.

A valve is only needed when the pump exceeds the overflow

To accomodate for the slower rate of water, i use a 7/8" U-Tube instead of the 1" that normally comes with the overflow. This prevents bubbles from accumulating in the U-Tube.

Actually, I'm not sure this is correct. An HOB overflow will drain water out based upon the configuration of the box, for example by using a 7/8" tube instead of a 1" you have changed the average rate of flow to less than 700. (this is probably why you have a good balance with a OR 2500 pump)

Its my understanding that the flow rate out of the overflow is only affected by the length of hose from the overflow to the sump, number of elbows and bends in the plumbing from the overflow, how the plumbing is run....i.e. a "roller coaster" effect will slow flow, obstructions in the drain hose like algae, surface area of the aquarium, and changing the siphon hose size like you have done. (which I might look into 'cept I bought a 2nd 1" tube)

I suspect that if your return pump is less than the output of the overflow that eventually your overflow will stop working as the water level in the aquarium drops. I do understand what you mean about the valve, its only needed to dial down the flow if the pump output is more than the overflow.

 

[twinspots_goby]

I would say Iwaki 30 will be another good choice.

 

[sjm817]

Blazin is correct.
Flow rate through an overflow is 100% determined by the return pump and associated plumbings GPH. Nothing else. There is a maximum flow rate that an overflow has which is determined by many factors. There is also a minimum flow rate that is largely determined by U Tube diameter.

Let say you have an overflow with a max flow rate of 600 GPH and a 1' U Tube which needs 200 GPH to keep bubbles from accumulating.

With a return pump that delivers:

337.5 GPH, you will have 337.5 GPH through the overflow. All is well.

615 GPH, you will have 600 GPH through the overflow, 15 GPH overflowing the display onto the floor. Bad. You would need to throttle the pump back a little to get below the overflows maximum capacity.

150 GPH will work for awhile until enough bubbles accumulate in the U Tube possibly causing a siphon break. Bad. You would use a smaller U Tube to decrease the minimum flow requirements, or increase the return flow.

 

[therealfatman]

I vote for a pump returning around 400 gph. The Ocean Runner 2500 is good, the maxi pumps tend to have volute leakage and breakage problems due to their design.

 

[Entropy]

I would go with a Rio 2100. 690gph, which will translate to about 375gph at 4' at 25 watts. Mine has been running problem free for about two years now.

 

[whowadat]

Yep, sorry about that Blazin but you are correct, my LFS set me straight on the overflow and how it relates to the return pump. Apparently I was looking at it as if I had a direct siphon out of the tank, if I was siphoning out 700 gph I indeed would need a return of 700 gph to keep everything in sync.

What I wasn't considering is that there are two compartments holding water with the HOB overflow, one in the tank and one outside of the tank which keeps everything equalized, one can't be sucking out more water than the other, so more water in equals more water out. (and visa versa)

As a matter of fact thank you Blazin for pointing me in the right direction, I now realize that the reason for my gurgling noises within my 120 are caused by too big of a pump in the return. I'm running a Mag 18 on a system designed to overflow 600 gph per overflow for a total of 1200 gph. Its been suggested I either need to put in a valve on the return or try using a Mag 12 pump. (which my LFS guy states works great on his 120 at their house)

So thanks again Blazin, and sorry for my ignorance.

 

[sjm817]

If you want a mag12, you can convert the mag18 to a mag12 by swapping in a mag12 impeller.

 

[whowadat]

Well, now I am a bit confused. In your earlier example SJM you noted that if you had a return pump that put out 615 gph and an overflow draining 600 gph you would end up with 15 gallons of water on the floor. If I'm using a Mag 18 returning in the neighborhood of 1600 gph +/- due to a 3' head pressure and each of my returns are only rated at 600 for a total of 1200 gph, why don't I have a major water flood on my hands right now ??

 

[sjm817]

Because with head loss and such you have less than the maximum capacity of the overflows. You dont have 1600 GPH. If you did, you would have water on the floor. To get that kind of flow from a Mag18 you would need large 1.5" or greater plumbing from the pump. If you are using small plumbing like 1", it really cuts the flow down.

What is the 1200 GPH overflow setup? How do you know it handles 1200 GPH?

No matter what the setup, you cant pump in more than can drain back out through the overflow setup.

 

[Nanook]

I have had Lifereef overflows on 40g, 58g and 65g tanks. I would not use a Mag Drive pump because they run too hot and too many watts. Being that your sump is only a 20g tank and your overflow maximum is 700gph, I would recommend using an Aquamedic Oceanrunner 2500 at 600gph. More than enough pump, good match for the overflow, quiet and cheap to run....not to mention reliable for the longterm