Anybody tried a gravity feed set-up for circulation?

[Delphinus]

I'm rather curious as the long-term effects of those. Specifically if you ever have to make minor adjustments. Like if your sump return pump gets a slight clog or whatever (in the case you have a strainer on the intake or something like that.) The theory seems sound, however. Have definitely seen some setups use that method, I had totally forgotten about it though. Thanks for the reminder ... I have to look into this some more myself.

(I still think using surge devices would be "way cooler" though )