I had this, and please if you can get another tank, do it! I bought this for Ben, I started smelling an awful plastic chemical smell in the water. Ben started getting sick for no reason so I took the tank back and got a 1.5g Tetra. He perked back up no problem!
If you do decide to get it, you can twist the top of the air pump and it will slow the current down. Just loosen it up and watch for the flow you like. Honestly, the filter does nothing but create a nice effect. It just sucks all the poop and whatever under the gravel, you still gotta take it apart and clean it out. Keeps the water moving though.
Taking the filter and tube out will make the light useless, as the light goes from the bottom of the tube up. If you cover that with rocks, no light :(