Years ago as a teenager I had several aquariums and have not had any since then. I am now looking to set up a 29 gallon aquarium and as with most things - there have been many changes through the years - and I'm sure the same is true with aquarium filter systems. I am wondering what you folks would recommend that is a good system and is affordable. In addition to a unit that I assume hangs on the back of the tank - should I also plan to have an under gravel filter/bubbling system? Any help will be greatly appreciated.