CL Planning. To Educt or Not to Educt?

CL Planning. To Educt or Not to Educt?

  • Quiet One 4000 Return & Quiet One 4000 CL w/o Penductors

    Votes: 0 0.0%
  • Quiet One 4000 Return & Quiet One 4000HH CL w/Penductors

    Votes: 0 0.0%
  • Mag 5 Return & 2 Quiet One 4000 CL's w/o Penductors

    Votes: 0 0.0%
  • None of the Above, they all stink

    Votes: 0 0.0%

  • Total voters


New member
I'm planning the closed loop for my next tank (65g) and I'm considering options and wanted to ask those that know more than I if I'm correctly understanding some of them.

My return will be from a Mag 5 or a Quiet One 4000 with 4-6ft of head (180-310gph w/Mag 5 and 600-700gph w/QO 4000). My current return is the Mag 5 but I'm considering a QO4000 to replace it for more flow after upgrading the sump volume. And I will also have a canister filter (200-300gph) with a hydor flo on the return.

Option 1
Quiet One 4000 (1017 gph @ 0ft, 50 watts) connected to the squid then to locline flared nozzles.
The efficiency of the squid over 400gph is stated to be 90% so my flow through it with option 1 would be 915gph.
915gph with a 50watt pump yields 18.3gph/watt

Option 2
Quiet One 4000HH (980 gph @ 0ft, 300 gph @ 12ft, 120 watts) connected to a SCWD squid and a penductor nozzle.

The idea of trying a penductor interests me, but I'm not sure if I'd actually gain anything from the extra cost in this case. Or if it would lead to problems. The penductor with a .30" oriface creates 5psi/12ft of head at 5 gpm or 300 gph according to the website. Does this mean the pump will see 12ft of head (not total, but from the penductor, slightly more from other factors) and will be able to produce 300gph of output? The squid would be at 5 psi as well, correct? 5 psi is the maximum operating pressure according to the manufactuer. That's the problem I foresee. But... The penductor with 5gpm of input should create an effective flow of 25gpm or 1500gph according to its manufactuer. And this is not taking into accoung the 80% efficiency rate of the squid at 300gph. That would bring me down to 1200gph. But is this how the penductor would work on this pump? Or would I get the 980gph through the penductor? 980gph -> 16.3gpm. According to the low pressure table from KTH that would yield a flow of about 80gpm or 4800gph from the penductor. And then consider the 90% rate of the squid gives 4320gph.

4800gph with a 120watt pump yields 40gph/watt
4320gph with a 120watt pump yields 36gph/watt

1500gph with a 120watt pump yields 12.5gph/watt
1200gph with a 120watt pump yields 10gph/watt

Which of these is a correct model to look at?

I'm basically looking for the highest efficiency from the pump as possible to lower operating costs, heat issues, and limit powerheads; and I'm not sure what the penductors do the equation.


Pump Head Curves

SCWD Squid Efficiency Chart

Penductor Low Pressure Pump Chart pressure eductor flow rates.pdf


New member
Looked at the watts/gallon issue also. I concluded that a high head pump with low gpm would = low head pump, high gpm.
I compared an iwaki 70rlz to a dart or ampmaster 3000. May be ther is a better formula to maximize the penductors, looked like a wash to me. I went the high flow low head option, because I wanted more volume, lower velocity flow. Hope some users will chime in and show the benifit of using the penductors.