I have a 26 gallon bow front tank with pebbles for substrate. My HOB filter is doing a good job of collecting any debries that's floating around but when I look at the bottom of the tank, I see a lot of fish poo and uneaten food. Is a underground filter a good option for me? I'm thinking if I have a UGF, I won't have to disturb my pebbles while getting all the nasties out of the tank. Also, the tank is pretty high up so it's a bit difficult for me to compeletly clean the bottom of the tank. Is this a good ideal? Pebbles are about the size of dimes and quarters.