I have a fluval 800 which is 68 litres. I have had it for a while now n I was thinkin about improvin the look with a line of bubbles at the back of it. What is the better air pumps to look at, not clued up at all on air pumps, dont even know how they work but wanna get one. I'm a cheap student n dont really wanna spend more than £20 on the new set-up. Cheers for reading.