size of pipe for drain and return on sump

[chocochipper]

OK so far I have built the sump and bought a used CPR CS50 overflow. The overflow is set up for 3/4" so that is what I got. But the question is should the return be the same size, bigger or smaller. Does it matter. I got no documentation and of course the guy just happened to be going on vacation so I can't really ask him. I looked at their site but unless I missed it I didn't see anything about it. And one more ?, what did you all use to cover the return line in the tank to keep all of the inhabitants from going in?

 

[johnnysalt]

Way to go on the diy sump!
My overflow tubing is 1 1/4" O.D. (outside diameter) and my return is 3/4" od....and all has been working great since I finished it! So, I don't think it matters UNLESS your overflow hose/tubing is so narrow that it can't keep up with the return pump? What is the gph of your return pump AFTER you figure the head of return (height from sump to top of tank plus the elbows at the end of the return). If I were you, I'd just use the same size for your return as your overflow....and see what happens.....they'l both most likely equal out though.
Oh yeah, I've never seen ANYONE cover their returns for fear of something getting in there....have you ever tried swimming upstream in a really fast moving river?!
Hope that helps....email me if you want!

 

[sonny]

While the size of the pump is the most important thing, so that the overflow can keep up with it, the size of the return pipe will determine how fast the water comes out of the return. The pump will pump what volume of water it can, say 500 gallons per hour (gph). If you use a bigger return pipe, you'll get 500 gph, but will look like it's slow. If you use a small return, it'll look like it's really strong current coming out of the tube. You will get the same effect if you use a large return pipe that is reduced down to a small outlet in the tank.
Sonny

 

[silent bob]

half-inch