How big return pump?


How big return pump do I need for 120g tank , internal overflow 1” drain , 1” return T pipe with dual loc line (1/2”), I bought Bubble magnus curve 7 protein skimmer, sump under tank , I’m planning on FOWLR for now


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Vinny Kreyling

Premium Member
You will have to figure your head loss to come close to actual GPH into the tank.
However Eheim is a great pump.
There is a calculator here for that.


Well-known member
With just a 1" drain (DURSO?) you will be able to handle about 300gph max without excessive noise. Assuming your sump is under the stand, you'll have about 4' of head pressure. Although the eheim 1262 is rated a little higher than that it is easy to reduce the flow a little with a ball or gate valve. Doing so will not harm the pump in any way.

FWIW - one of my 1262's I got in 1988 or so and it was used then. Other than yearly cleanings and a impeller replacement or two, it is still going strong. I use it as the return on my 120gDT but have a 1500gph overflow (2 x 1.5") and use a 3/4" return from it so it runs wide open.


Fish store told me to get DC pump 1350-2100gph (I got) I want to get sump ecoshop 26g which is rated for 1250gph . I have bubble magus curve 7 skimmer. Will drain keep up with sump and return pump . Or should just get smaller pump 1200gph . 1” emergency 1” durso drain 1” return T with 2 lock lite .it’s so confusing thanks for responds

Vinny Kreyling

Premium Member
While a Durso might not keep up a Herbie style will, it handles more flow.
Be Sure to use a GATE VALVE.
A DC pump is usually variable flow & can be used to get the "right' flow.
As far as a sump, you want the biggest one that fits under the tank because they generally run around 1/2 full.