Or do what I used to do. It takes practice, but it works ALOT easier than running a tube.
Fill up the overflow box on both sides as much as you can.
Put the u-tube in the water and fill it all the way up.
Keep the u-tube it in the water and then wrap some plastic wrap on both ends of the pipe so no water leaks out. (The bigger the pieces the better so that you can get a good grip on them...)
Put the pipe in the overflow and then pull out both pieces of plastic wrap as fast as you can.
I GUARANTEE it will work. Just be quick about it because the plastic wrap will let out some water.
I did this on my old tank all the time.
