Wet/Dry Filter help

[kdblove_99]

I just bought a used wet/dry system and its the hook on back of tank kind. Theres the tube that sits in the cant canister part and it also is on the back part canister on the outsidce of the tank. I heard water needs to be going through there before you turn it on. how the heck do you do that i stuck a piece of air hose through the tube into the inside where the water is now but i cant get it to continue to flow.

[somefinnfishy]

I'm assuming you talking about some kinda overflow U tube both ends must be in water to get it to siphon when you suck the air out if you lift either end out of the water to remove the air tube you break the siphon thus stops flowing.
Fill the HOB wet/dry thingy to the top with water first then try to make the siphion.