I and think of replacing my back up filter on my 72 gallon, currently I have a fluval 405 and a ac 70 on the tank. The ac 70 makes to much noise even after replacing the motor an impeller.In the picture on the box for the 400 it looks like the intake tube is much shorter than the ac. Does anyone know if extension tubes are availible. Would the filtering by affected by a shorter tube? I thouht it was better to have the intake closer to the bottom. Also is the emporer pretty quite? Does it make noise when the water hits the tank due to being spun off the bio wheel?