This is my second attempt at a homemade "kreisel" tank. My first attempt was over powered and overkill. I decided one large side is better than 2 smaller cubes, even if the math was prettier the other way (oh, the trials of being married to an engineer). Using a 35 gal acrylic tank (the 1st tank I got with my own $, I worked a whole summer at the "Chicken Coop" frying chicken and shrimp at the tender age of 15 for this baby) I glued a plexiglass panel into one end. The panel had a hole cut out of the center with a piece of filter sock over it so that I could place a power head into the smaller chamber without the babies getting in. I also glued 2 more pieces of plexiglass into the bottom corners of the larger side of the tank, so that the bottom corners have been replaced with angled sides. I retrieved my old Sea Clone from the pile of papers it was holding down and using just the power head and tubing was able to put the intake on the smaller side of the tank and the outflow into the babies' side. I then attached a pvc tube with holes drilled into it onto the outflow tube. I also took the flow regulator from another old power head so that I could adjust the rate of outflow. The result (theoretically) is a tank that has one side housing live rock, a heater, an air stone and the power head. On the other side a circular flow is (sort of) achieved by the low flow being directed by the angled panels. If I wanted to, I could probably figure out some way to set up a filter on the "safe" side, but I'll keep you posted on that one! I am going to keep most things the same between the two tanks as far as clipping macroalgaes to the sides, the feeding routine and schedules, lighting, etc. MESSAGE TO ALL VISITING THIS FRINGE OF OUR FRINGE: If you can think of things to try differently between these 2 experiments, let me know! I just happen to be the one with the livestock at the moment, but I sure don't have all the best ideas!!!