New return pump - elbows on inlet or outlet?


Premium Member
I just got a reeflo bh1450 for my new sump in the basement project. Because this pump goes in one side and out the other there is a need for some 90 angles right before, or after the pump and im thinking before would be better, but the manual only talks about not restricting the inlet, not outlet?

Coming out of the rubbermaid sump will be an immediate elbow to put the plumbing along the sump, then I can go into the pump and then after the pump and about 6" will be a 90 elbow (to go up a wall, through the wall, toward the DT, then up again to the DT, and another 90 or 2 depending on how I get the water plumbed into DT).

The other option would be to secure the pump to the wall facing up, which would then be an immediate 90 out of sump, then another 90 to start going up the wall and into the pump.

The pump will be below water level either way so gravity will feed the inlet no problem - just not sure if its best to have one of the 90s before or after the pump. With all the 90s and head pressure id like to reduce as many as possible to increase flow.


Refugium pat.#D414,242
I used spa flex with mine:)
Not shown in picture but you can see where it goes and how i plumbed my BH 2700's. This is the right side of my close loop set up but would do the same with my return plumbing even though i am using a Maxflow for that.


New member
there is a 10D rule to stabalize water in a pipe 10 x the diameter so if it's one inch pipe you need 10 inches of straight before water hits the impeller. If the water is not laminar or smooth the impeller will wear unevenly and its lifespan will be drastically reduced it's called cavitation. No issues with restrictions after the pump. So you can have a 90 so long as it's a length away from the pump. Also if you increase the diameter of the input you can shorten that distance.


Premium Member
Excellent - really good info, thanks! When you say a "length" after the pump is that another 10"? Im thinking the ball valves take up at least half of that on each side. Also on this bh1450 pump the inlet and outlet are both straight, unlike a lot which are in one side and then up - so guessing they know there will almost always be a 90 pretty close to the outlet since all of our tanks are usually above the pump!