flexible vs. hard tubing for sump

[StephNewman]

I see a lot o people using hard tubing instead of flexible. Is there a reason for this? Does hard tubing effect how the water will flow through it?

[kbmdale]

I used it on some of my return because the pump will cause a vibration in the return line and make a humming sound where it connects to the sump. The flexible keeps this from happening.

[supertech3]

Hard tubing does not have all of the ribs that flexible does, thus will not having different particulate accumulations associated with it.

[xtrstangx]

I plan on using flexible PVC with my 75g setup, just because I'm running a basement sump and the drain/return won't line up perfectly.

It also helps to reduce vibrations. You can get potentially more flow out of it than hard PVC, but you have to have more space (consider doing a 90º angle.. 3/4" in regular PVC, a foot or two in flex PVC)

[RokleM]

I use flex anywhere I need to potentially move items and to cut down areas where solid would restrict flow (use a curve flex instead of a 45 or 90 hard).

[a4twenty]

i used the flex for my basement sump, and on my pump side there is only 1 90 ( in the tank ) the rest are nice gentle curves. i don't think the ribs make a big difference, actually i think the help kind of like rifling in a gun barrel.