I have been searching the web for ways to slow the current from the filter in my 10 gallon tank. I came across the soda bottle fix many times. So I tried it out. It helped some... But not what I was hoping for. My betta was still swimming kind of hard and it was pushing his food around and down to the bottom of the tank. No good. So I decided to try using the bottom of the soda bottle. I taped it to the front, over the output. With a lip of it hanging down in to the water. This directed the current to the back wall of the tank. Perfect! It works great and doesn't send a current across the tank. My only problem at first, was that the lid of the tank wouldn't fit. Only by maybe a half inch. So I trimmed the plastic down some, and now the lid fits. When then lid didn't quite fit... It wasn't very obvious or hanging over the front. So it wasn't too big of a deal.