A siphon is a tube that allows liquid to travel upward, above the surface of the origin reservoir, then downwards to a lower level without using a pump. When a certain amount of water moves over the bend in the siphon, gravity pulls it down on the longer leg lowers the atmospheric pressure in the bend of the siphon.

Why is my siphon not working?

You may have an air leak in the tube somewhere that is preventing the siphon from getting going. Any tube would work, just put one side in the higher container, suck the water through and put the other side of the tube in the lower container. It's simple physics. Don't suck it, you'll end up with a mouth full of water.

Can a siphon work uphill?

Water in a siphon can flow uphill too, as can a puddle of water if it's moving up a dry paper towel dipped in it. Even more curiously, Antarctica has a river that flows uphill underneath one of its ice sheets.