I just used the stock tubing and cut it in half. It has a loop in it and doesn't impede the flow. The FX4s will have even more flow with shortened tubing lengths, which I am planning to do when I can get the clear 1" tubing. I might also place a cap with perforations in it over the intake piping in the overflow. This tank will have larger fish in it so any fish getting sucked into the intake of the filter is not likely so I don't think it is necessary so for now I will leave it alone.