return pump eheim 1250 for 30g

[mivph1]

Hey guys,

 

I am looking at the eheim 1250 (317gph) for my return pump in my 15 gallon sump to my 30 gallon display tank. My sump is on the floor next to my tank. So i got a 6 feet head. I might be wrong but i read that it's better to have a low flow in the sump. I also have enough flow in my display tank from two koralia (1450 +550) So i don't mind having a low flow rate from the return pump.

 

Is this pump have enough power for a 6 feet head or should i get a 1260?

 

Thanks!!

[seabass]

The 1250 has a max head height of 6'7".

 

Here's the head height chart for the 1260:

 

How much flow do you want at 6' head pressure? For example, a Mag 3 or Mag 5 puts out 180gph, and a Mag 7 puts out 400gph. A Mag 3 is only $60, while a Eheim 1260 is over $100 more.

[nibor]

How did you work out you have 6 foot of head loss?

 

What is the vertical distance between the water surface in the return section of the sump and the display. Can you describe your plumbing?

[mivph1]

How did you work out you have 6 foot of head loss?

 

What is the vertical distance between the water surface in the return section of the sump and the display. Can you describe your plumbing?

 

My 30 gallon is tall at 24 inch height and it's not on a standard aquarium stand. That's why it's a 6 feet head loss. The vertical distance is approx. 1-1.5 feet. I calculate the head loss from the bottom of the sump to the water surface of the display tank.

 

As for the eheim, i heard they were really silent since the system is in my bedroom. I need the pump to be dead silent.

 

Thanks!

[MikeTR]

I'd take an eheim over a mag any day. I think you'll have more than enough flow, probably need to put a ball valve on it to dial it back even more.

[seabass]

As for the eheim, i heard they were really silent since the system is in my bedroom. I need the pump to be dead silent.

How much flow are you shooting for? What's your overflow rated for?

 

It looks like the 1260 would give you about 300gph at 6ft head pressure.

 

It will actually have more than six feet of head pressure due to plumbing bends. This could be important if you choose a 1250 (which might not be able to pump any water).

 

Choosing the right flow rate for a particular overflow, and choosing the right drainpipe, might be more important for noise. I think that normally, drains are noisier than return pumps. Skimmers might be the noisiest piece of equipment, followed by fans.

 

It's possible to keep a fairly silent tank if you plan well. Have you considered running the tank without a sump, skimmer, or any fans?

[mivph1]

Thanks guys. Your comments really helps me since my LFS don't seem to know anything.

 

I didn't buy the overflow yet. I am looking at the tunze overflow rated at ~300 gph or maybe buy a eshopps from ebay. I'm not sure yet. Let's say the overflow is at 300gph. Do i really need a 300 gph at 6ft head pressure? Can i have 100 gph at 6ft head pressure since i already have 2000 gph from my two powerhead?

 

@seabass. I don't plan of having a tank with no skimmers and sump. I like the idea of doing less maintenance.

 

Thanks again

[nibor]

My 30 gallon is tall at 24 inch height and it's not on a standard aquarium stand. That's why it's a 6 feet head loss. The vertical distance is approx. 1-1.5 feet. I calculate the head loss from the bottom of the sump to the water surface of the display tank.

I guess when you say vertical distance there you mean horizontal which is not going to have much affect on the flow rate here. The head loss is not the distance from the bottom of the sump to the water surface of the display, it is the distance from the water surface in the sump to the water surface in the display plus pipe losses. So, if you tell us the vertical distance from the water surface in the sump to the water surface in the display we can work out how much flow you are going to get if use big enough pipe work.

 

How much flow are you shooting for? What's your overflow rated for?

 

It looks like the 1260 would give you about 300gph at 6ft head pressure.

 

It will actually have more than six feet of head pressure due to plumbing bends. This could be important if you choose a 1250 (which might not be able to pump any water).

 

Choosing the right flow rate for a particular overflow, and choosing the right drainpipe, might be more important for noise. I think that normally, drains are noisier than return pumps. Skimmers might be the noisiest piece of equipment, followed by fans.

 

It's possible to keep a fairly silent tank if you plan well. Have you considered running the tank without a sump, skimmer, or any fans?

This is all good information but in this case I very much doubt there is 6 foot of head. Friction losses are pretty much inconsequential if the return plumbing is of large enough diameter as this keeps the velocity low. Like you say, the key to this is the question "how much flow are you shooting for"?

[seabass]

It's been awhile since I've read this, but here is an article that might help you with head pressure:

Pump Head Loss Calculator - Easing System Design

 

Let's say the overflow is at 300gph. Do i really need a 300 gph at 6ft head pressure? Can i have 100 gph at 6ft head pressure since i already have 2000 gph from my two powerhead?

Most overflows for drilled tanks are rated at the maximum flow they can handle without flooding. It would actually be dangerous to run one of these overflows at it's max rating as a slight restriction could cause a flood. Plus, running them at the upper capacities usually means they will be noisier.

 

I usually tell people to cut it in half. For example, I would run a 300gph overflow by pushing 150gph (or less) at pressure. I'm not sure if it's the best advice, but it has worked fairly well for me. By reducing the flow, the noise tends to be less.

 

Yes, you are right; tank flow is primarily provided by powerheads in the tank (and not the return). Although you do add that when computing your total flow.

 

I don't have complete trust in HOB overflows, so I'm not sure how they are rated. I would think that they have a recommended flow rating as opposed to just a maximum rating. For an HOB overflow, you would need to make sure that you comply with the recommendations as best you can.

 

@seabass. I don't plan of having a tank with no skimmers and sump. I like the idea of doing less maintenance.

I see. I didn't know how committed you actually were to a truly quiet tank. Then your skimmer will probably be your noisiest piece of equipment.

[mivph1]

It's been awhile since I've read this, but here is an article that might help you with head pressure:

Pump Head Loss Calculator - Easing System Design

 

Most overflows for drilled tanks are rated at the maximum flow they can handle without flooding. It would actually be dangerous to run one of these overflows at it's max rating as a slight restriction could cause a flood. Plus, running them at the upper capacities usually means they will be noisier.

 

I usually tell people to cut it in half. For example, I would run a 300gph overflow by pushing 150gph (or less) at pressure. I'm not sMure if it's the best advice, but it has worked fairly well for me. By reducing the flow, the noise tends to be less.

 

Yes, you are right; tank flow is primarily provided by powerheads in the tank (and not the return). Although you do add that when computing your total flow.

 

I don't have complete trust in HOB overflows, so I'm not sure how they are rated. I would think that they have a recommended flow rating as opposed to just a maximum rating. For an HOB overflow, you would need to make sure that you comply with the recommendations as best you can.

 

I see. I didn't know how committed you actually were to a truly quiet tank. Then your skimmer will probably be your noisiest piece of equipment.

Thanks! I'll take your advice and go with the 300gph overflow and cut it half to 150 gph. With nibor information, it's seems that i have 5 feet head loss. So the eheim 1250 is at ~150 gph for 5ft loss.

So, I'll buy the 1250, it seem to fit perfectly with the overflow.

[nibor]

The output on those pumps is for 1/2" tubing. Use one of these with as short a piece of 1/2" as possible and step it up to 3/4". If you use 1/2" tubing for the whole return, you won't get anything like 150gph, likely closer to 100gph. I reckon you will get about 140gph with a 3/4" flex return.