On all my XP series, I use the bar type return and keep it about 3 or 4 inches below the surface Erraticichlid. When I do major water changes, the distribution header is often above the surface anad it is nioisy enough that it would drive me nuts to run it that way all the time. There are lots of XP answers here on there web site. http://www.planetrena.com/Filstar-Rena-FAQ.html#Filter%20Setup
