One word of advice...don't get a Fluval 404. I bought one, and it filters ok, but it's a pain in the butt to get working. I also bought a submersible fluval 4, and I am very happy with it (the 4 is about $35 vs. the 404 @ $125). My advice, get two submersible fluval 4's.
:I am about to buy a fluval 404 for use in a 30 gal tank setup. My question is, can I hook the Intake tube to an under gravel filter port? Iím worried that if I just put the tube in even with some sort of screen on it that it could catch and trap my little one in it. Would this work, or would the undergravel setup damage the filter, or hurt the efficiency of it?