I will be getting an acrylic 180 very soon. Six by two by two. I already have the 120 for the sump. I will be trying a few new tricks on this 180 and using some old favorite stuff as well. For those of you who don't visit, I'll bug my friends to take some pics as the build progresses. I'll post this build here and at www.reefhobbyistmagazine.com and that's it. First of all, after hearing Rich and Gresh go on about Geyer (sp?) systems, I finally went back and read the RDO mag (Advanced Aquarist iirc) from Jan where they talk about this system. Very inspiring, and anyone who's ever spent time with corals in the wild can tell you they're no strangers to direct linear flow (part of the Geyer principle actually). But I don't want a huge sheet of acrylic to divide my tank so I've taken the baffle and lowered it so it can be a shelf for live rock to sit up on. Perhaps 3" from the bottom in the front and rising to 5" over 1.5'. So this angled shelf for rock will have a couple of penductors strapped to the bottom angled to deflect off the bottom and roll flow up the front face of the tank. I will use a pressure pump CL to power these.At the ends of the tank, I'll return down the back wall from the sump. This will be the higher velocity return (as opposed to the peductors far greater volume but lower velocity). If it all works, I should have a constantly rolling fat center of water further accelerated by the high velocity returns from the sump. Plans are currently for a 4' Calfo style o/f but since the 180's eurobraced, maybe I'll go 5'? Stay tuned for part 2 of "Jims' bad idea" Next:"Norm and Jim build a stand!" All comments, questions etc... are welcome!