2 return pumps?

[reefjunkie42]

hey i am starting a new system and need to figure out if my ehiem 1262 is enough for the return pump. i currently have a 90 gal and am upgrading to a 180 gal. any opinions? i am going to go with another ehiem if i decided to go with 2. i will also connect ball valves to both to control flow

 

[reefjunkie42]

bump

 

[davocean]

1262 is what I ran on both of my 180's and ran just fine.
Unless you have an unusual amount of travel/head pressure it should be plenty of flow, no need for a second one.
Always keep in mind watts = heat, so w/ that in mind I would not go overkill on return.

 

[Nova101]

It is also good to think of your tank as an investment that should be protected.

If your pump fails, what will be the impact?

Do you take vacations? What if the pump fails while you are on vacation?

Following that logic, 2 pumps are better than 1.

 

[reefjunkie42]

there is no extreme head pressure just 6 ft or so not basement to living room type deal. I was just thinking about the turn over rate of the system. I know water circulation is important and it is going to be an SPS tank. I just want to make sure 758 gph will be enough for a 180+40 sump. Ehiems run extremely cool so there is no real heat issues per-say, well not in my experience with them atleast

 

[davocean]

It is also good to think of your tank as an investment that should be protected.

If your pump fails, what will be the impact?

Do you take vacations? What if the pump fails while you are on vacation?

Following that logic, 2 pumps are better than 1.

Many things can fail, including your tank itself.
There are some things I do have back ups for, but not many of us have 2 of everything.
A better approach would be to test for such things as power loss.
If my return failed, not a disaster, just water level would be a couple inches lower, my PH's would still be spinning.
If I go on vacation(just happened to get home last night from one) I have someone check on and feed my fish, and have an extensive emergency contact list that includes fellow local reefers and my local site.

 

[davocean]

there is no extreme head pressure just 6 ft or so not basement to living room type deal. I was just thinking about the turn over rate of the system. I know water circulation is important and it is going to be an SPS tank. I just want to make sure 758 gph will be enough for a 180+40 sump. Ehiems run extremely cool so there is no real heat issues per-say, well not in my experience with them atleast

Your return typically should be about 3-5x turnover.
The rest of flow needed from loop or PH's, and probably 50-60x turnover minimum on heavy sps, some do much more.
The 1262 is closer to 900gph, your number may account for headloss I'm guessing.
The Eheims do not add much heat if any, but I still try to keep watts down, as heat is one of our most common issues, and I'm an "every little bit helps" person on this, and I think most experienced reefers would agree w/ me on that.
I just don't see a need for a second return, but do what you think feels best for your own needs.

 

[jcw]

I use 2 1260's for my return on a 125g.

Yes, the turnover in the sump is too high, but it's great for oxygenating the water and getting flow through the chaeto.

However, two eheims use a lot of watts compared to powerheads in the tank. Maybe 10 times as much.

But I like the redundancy of the two in sump returns. If one does fail, I can easily manage with the other one until I get a second one ordered. And do maintainence one while the other runs.

Heat is not an issue for me even with 2 in the sump. I have a 1250 running in my salt mixing station constantly and it stays cool. Eheims are great in that respect.

 

[northbay-reefer]

What are the benefits of having two pumps?

Pros
1, redundancy
2, more turn over rate
3,
cons
1, using twice as much power
2, more equipments to maintain
3, More plumbing

The pros of having two pumps can be solved by installing a power head like a Tunze inside the tank for better flow and put it on a battery backup in case the power goes out. This method also help when their is a power failure.

I vote for using one pump, if you want to have an extra pump as a backup so you can swap it out quickly then keep one on hand (that's what I currently have)

 

[Alsshon]

You can always use two equally powered overkill-pumps and reduce the flowrate to half with ball-valves. Magnetic driven pumps reduce their power consumption when the flow is restricted. This way you can use pumps and avoid the overheating of water at the same time because the pumps are running at lower wattage than normally. Also you have some lifting power in reserve in case the other pump fails.

 

[LouH]

I personally run 2 Eiheim 1260s as returns on a 120. One is split to supply water to a refugium. I'm considering the purchase of a big UPC to run the one split Eiheim in the event of a power outage. I already have one for the Tunze PH in the main display, but I don't want to lose my refugium or the DSB that it overflows into. A UPC of that size will be around $1K, but considering the time put into the livestock, it is worth it to me.

 

[BeanAnimal]

You can always use two equally powered overkill-pumps and reduce the flowrate to half with ball-valves. Magnetic driven pumps reduce their power consumption when the flow is restricted. This way you can use pumps and avoid the overheating of water at the same time because the pumps are running at lower wattage than normally. Also you have some lifting power in reserve in case the other pump fails.

All centrifugal pumps use less power with the output falls. The problem is that the curve is not linear. So if you valve a centrifugal pump back by 50%, you do not also reduce power usage by 50%. In fact, you lose efficiency (dependig on where on the pump curve your operating paramaters fall). That is lets say at 100W you get 100GPH. Valved back to 50GPH, you are using 90W. So you reduce the overall power consumption by 10% but decrease flow by 50%. You go from 1W per gallon pumped to 1.8W per gallon pumped (in the example).

 

[johnike]

Two Mag 12's spittin it back from my sump, with ball valves full open. Going on 7 years. Think I'll take them out and clean them someday!

 

[Alsshon]

All centrifugal pumps use less power with the output falls. The problem is that the curve is not linear. So if you valve a centrifugal pump back by 50%, you do not also reduce power usage by 50%. In fact, you lose efficiency (dependig on where on the pump curve your operating paramaters fall). That is lets say at 100W you get 100GPH. Valved back to 50GPH, you are using 90W. So you reduce the overall power consumption by 10% but decrease flow by 50%. You go from 1W per gallon pumped to 1.8W per gallon pumped (in the example).

Thanks for the correction. This is interesting, do you have some kind of articles or references to link here?

 

[BFG]

For me, I would try to match the return pump flow rate with my skimmer pump flow rate. Too high flow passing the skimmer would assist the algae to have an increase of food source. Wave maker in the tank would take care of any flow issue, including assisting of oxygenation of the water but not at a primary level.

 

[BeanAnimal]

Thanks for the correction. This is interesting, do you have some kind of articles or references to link here?

There really is nothing to link, it is just a basic fact describing the operational characteristics of a centrifugal pump.

You can look at any centrifugal pump curve and see a graphical representation of the flow to power ratio at any given head pressure. You will also notice that there is a point, at which any head pressure above or below it causes a loss of efficiency. This is called the Best Efficiency Point or BEP. BEP is defined as the point where the pump's performance curve intersects its system curve.

 

[LouH]

If you want to experiment there are watt meters that you plug into a standard outlet and then plug the test device into that. My buddy has one, and he demonstrated this exact phenomenon. I believe the device is called a Kill-A-Watt or something similar.

 

[LouH]

Another thing that you can do, and I've done this, is to purchase an inexpensive extension cord of sufficient wire gauge, cut away the insulation so that you can separate the three wires, place it between a wall outlet and the device being tested, and then measure the amps by placing a non ground wire inside the jaws of the meter. I did this for my entire tank and discovered that it had a draw of 12 Amps. Ouch!

 

[reefjunkie42]

i have 2 mp 40s for waves im just wondering about turn over rate and if i need to add another pump for this. i was thinking of feeding a carbon and gfo off each return as well. that way id be getting rid of 2 pumps for the 1 ehiem. id install ball valves ion both for added protection and to dial them back if they were to strong.

 

[eums]

you could always run a laguna pump, they are energy efficient, quiet and reliable.

IE an atb flowstar 1500, I have one on my tank and it puts out a ton of flow. its the same flow as a Eheim 1260 + 1262 but uses a smaller footprint and much less electricity that the 2.
over 1500gph at under 90w is hard to beat, realistically mine is putting out ~1200gph at 5' head and using a bit under 80w