I am putting together a couple of tanks to be joined with a fish bridge. I have a 20 gallon long tank, a 10 gallon standard tank. My tube is 4 inches in diameter by 36 inches long with bilateral elbows. The question I have is this: Will having one tank being 20 gallons and the other tan 10, will I end up with no negative pressure or if I do, will it all empty into one of the tanks leaving me in a drowning mess? Im not a rocket scientist and physics isn't something I ever took in school. Please advise, if possible.