Will be setting up a 20 gallon long tank to house 6 to 8 cories. The tank is only about 12 inches tall, so I'm a little confused about the 160 to 200 gph suggestion for HOBs, and the length of the intake tubes on these larger filters. Right now I'm looking at the Fluval C3, rated at 153 gallons gph, with an adjustable flow. Read in a review that the intake tube is 16 inches long. Would I cut the tube, go with the C2 or find something else?