[Mark Brown]

So this might seem a little brain dead to most people and I cannot say I was terribly surprised at the results however I just wanted to pass on my two cents.

This evening I switched the return line from my sump from 90° elbows to 45° and holy what a difference. That small change gave me almost 1/3 more return from my sump pump. I measured the time I took to return the water from a 5 gallon pail doing pwc for a comparison so it isn't super scientific, just my 2 cents.

 

[SeaHorse_Fanatic]

Actually just went through the same thing with another member. Sold a powerful return pump but his plumbing had a 90 degree elbow right out of the sump and no water was getting to the top. Redid his plumbing to remove that elbow and voila, water is flowing up at 7' head.

 

[Mark Brown]

it is amazing what a bit of friction can do. I honestly think I came closer to doubling flow but I didn't want to sound like a liar

 

[SeaHorse_Fanatic]

Well his went from zero flow to working perfectly to supply water for a multi-tank system with a 7' head. So yeah, 90 degree elbows are real flow killers.

 

[dragonshrimp]

It may be "common" knowledge, but sticking it back into the collective consciousness every so often can be a very good thing. I am in the middle of a shrimp rack/sump/refugium build and I can't say if I had duly considered how any 90-degree angles would affect the flow. I definitely will now! Thanks for the reminder!

Sent from my XT1585 using Tapatalk

 

[Mark Brown]

It may be "common" knowledge, but sticking it back into the collective consciousness every so often can be a very good thing. I am in the middle of a shrimp rack/sump/refugium build and I can't say if I had duly considered how any 90-degree angles would affect the flow. I definitely will now! Thanks for the reminder!

Sent from my XT1585 using Tapatalk

At long last I am helping!!

 

[Thaim]

Actually just went through the same thing with another member. Sold a powerful return pump but his plumbing had a 90 degree elbow right out of the sump and no water was getting to the top. Redid his plumbing to remove that elbow and voila, water is flowing up at 7' head.

huge difference! I didn't realise what a difference it would make until I redid the plumbing. I have 5 tanks running on 1 return line and I removed the 90's I didn't need and im getting the perfect amount of waterflow now.

 

[gklaw]

You could also turn a 90 with two 45 or better yet use electrical CPVC bend (use proper transition cement). It is not so much the degree but the way it is transitioned.
In typical 3/4 or smaller PVC 90, the water is pushed against a dead head with no transition at all.

For return pumps, there is no rule to say that the pump has to sit flat. Turn the pump 90 or 45 degree so the water shoot straight up - just to make sure it does not generate enough vortex to suck in air.