I have a five-gallon tank for my new Betta, Boris Karloff aka Fishy Fish. I got him a sponge filter as the one that came with the aquarium package would've caused a lot of turbulence. I got a Tetra pump, rated for 10 gallons. I'm doing *something* wrong... The filter gives off just a couple of small bubbles every 30-45 seconds (I timed it). What is wrong? I asked The Guy at Tong's Tropical Fish (my favorite LFS), and he suggested putting the air pump higher than the tank. What do you think of this advice? No matter; it didn't change anything. Could I have put the check valve into the hose the wrong way? Unfortunately, I recycled the package already, and don't remember where the arrow is supposed to point. Is the sponge just too much for this pump? I have the smallest filter I could find. What could it be? I surely appreciate your suggestions and advice.