How big of a return pump do I need?

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workhz

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Not sure head height is a minor loss or maybe it’s more for DC pumps or something just odd with my pump.

On my tunze 1073.050 (on a 90 gallon) is rated at about 800g/h. At a head height of 1.5M, the graph shows I lose about 40%. Don’t think that’s minor.

My stand is 39” tall plus the tank is 24”. Pump is about 6” off the ground and return is maybe 1” below top of tank so a 57” head height. Don’t think it’s that unusual of a set up.

Is this type of loss more a DC motor thing or do the AC motors have as significant of a drop?
 
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KStatefan

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Not sure head height is a minor loss or maybe it’s more for DC pumps or something just odd with my pump.

On my tunze 1073.050 (on a 90 gallon) is rated at about 800g/h. At a head height of 1.5M, the graph shows I lose about 40%. Don’t think that’s minor.

My stand is 39” tall plus the tank is 24”. Pump is about 6” off the ground and return is maybe 1” below top of tank so a 57” head height. Don’t think it’s that unusual of a set up.

Is this type of loss more a DC motor thing or do the AC motors have as significant of a drop?

Yes there is siginafint drop with an AC pump. Is is all in the design of the impeller and volute. When you add a manifold the head loss could be minor compare to the friction loss thru the piping and reactors.

Reeflo.jpg
 

Quietman

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DC Centrifugal pumps will still have pump curves. At 1/2 max height the Vectra M1 pumps less than 50% of max rated flow. I also have the Tunze 1073.05 and it does as well.

This characteristic is common to all centrifugal pumps (which is what we use for return pumps). The impeller design can result in a high pressure pump (which can pump at a much higher pressure (relative) but flow will drop off rapidly or high flow/low pressure or something in between. All of these can be useful to us depending on what's needed. See the below pump curves for Iwaki to illustrate the difference using same motor. Z being high head, X being high flow compared to standard which is in middle.

Iwaki 30 curve.PNG


The dosing pumps we use are typically positive displacement pumps which have no shut off head and require relief valves (internal/external) or other methods to prevent damage to systems. These have slower flow rates.
 

rusty hannon

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I am planning for a 150 gallon tank. Since return pumps should be 5-10 times per hour, I would search for a 1,500 gph pump. If I wanted to plumb in a manifold for three future add-ons (reactors, etc), do I need to increase the return pump gallons per hour for the requirements of the add on? Let me know if my question is poorly worded and I'll clarify.
We base our choices by turning tank over 10 x per hour if seahorses 20 x per hr
 

jetskiwilly

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Sorry to hijack a thread. Setting up a 90 with Jebao 8000. Plan is to run in 1-1/4” line for return. Wondering if the extra 1/4” vs 1” is worth the extra headache finding fittings and added cost. Have (2) 1-1/2” drains. Plan to make one a 1” drain and other full size 1-1/2” for emergency drain. Drain is directly down, no turns.
 
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jetskiwilly

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I’m getting my intakes and returns confused. Drains plan is 1” with gate and 1-1/2”. Return (connected to pump) should I go 1-1/4” or just 1”? Return plan also to split to 1” Y loc-line with random flow nozzles.
 

jda

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1500 GPH though a sump is no joke. 750 might be more when you end up. Put at least one heater in the tank hidden out (it gets covered in purple anyway), so that you don't HAVE to ramp up the flow through the sump. For stuff like reactors, skimming, etc, 50% of tank size is plenty with the surface skim and everything.

Under stand pumping is really not that hard and many pumps can handle this well. Reliability vs features combined with cost is likely going to be your key decision.

I am a AC return pump guy... just cannot risk any failures with pumps that have a short history. Most DC pumps have not even been out long enough to know if they are reliable yet, and nearly all have had many revision because they were not. Fluval SP4 or SP6, Laguna Max Flo have been running for years and years with no issues. I use Eheim too. They are low wattage. I have no use for speed control nor for feed mode, so that kind of stuff does not matter to me.
 
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