On my Fluval 404, the intake tube is too long. (The hose attaches to the tube, and then there is the grate-thing at the end to keep at big debris) The tube is almost as deep as the tank, and I am using sand in the tank. I have it angled a lot right now, but it doesn't attach to the suction cup very securely, and I'm worried it could get knocked off and suck in a ton of sand. Can I cut the tube to the right length, like with a hacksaw? It seems like plastic, but I don't want to crack the whole thing by accident.