Thanks a lot for the kind words. I guess it could be used on top of a tank but with the lights its pretty heavy. Not sure how much heavier it will be with the pipe/screen and water running through it. I made it to sit under my tank. I'm gonna build myself a 10-12g sump. I built this ATS to be a strong filter for 36g of water (ATS Jedi Master, SantaMonica, confirmed it would). Now I just need to figure out which is the best way to set up my sump. I was thinking of setting up a 3 wall bubble trap on the drain side and a single wall with teeth for a small return area.