Recently saw this vid and loved how to filter basically disappeared. I have a 20 long and want to do the exact same so my main question is could I put some bio balls behind it? That way I could just use some from my other filters and cycle instantly, maybe add a small air stone underneath the bio balls? Also would this type of filter be sufficient for a fairly stocked tank. I plan to do 1 f8 puffer and at least 5 bumblebee gobies. ( ik brackish my LFS sells them in fw so I'll need to slowly add salt over the weeks)