How Auto Siphons Work As Seen in Vid Below

[LivingLegacy85]

HFB! What's going on?

So i've been wondering how the whole auto siphoning thing works. I want to implement the style shown in this episode of DFT.

How the heck does this actually work? I know it deals with gravity, but I need to know specifics.

How high or low to cut the pvc. How to drain the water to a certain level etc.

Can anyone help me out with some resources to help me understand this?

https://www.youtube.com/watch?v=oYZXfdn0Usg (Vid Link)

[troy tucker]

He has a big fish room with running water and a drain in the room. very nice. Most of the plumbing he uses is like mine but mine never come out of the tank. ones the siphon is primed it's like turning the water on and off. it is easy.

[ptran]

I like the plumbing part where he can adjust for the water level.
I have 2 water snakes for my water change, 1 to drain and 1 to fill. I'm also use a utility pump to get the water out faster.