When I became that we were going to have pelagic octo babies on our hands, the answer was obvious. I had to convince my husband to build me a kreisel tank. We found a great site www.jelliquarium.com/ that have small kreisels for growing out pelagic fish- $500. But the pictures are free to look at and gave us some good design ideas. We used an old 35 gal acrylic tank and built it so that it had two sides and a center chamber. My husband thought that two square tanks that would give the most circular flow. The walls of the center chamber were made of small plexiglass sheets that had windows cut out and covered with "Lee's " filter socks. The bottom corners of each side tank then had plexiglass "baffles" glued into place, we used acrylic aquarium sealant for all of the "gluing." We sunk a "Rio 1100" power head into the center chamber then got tubing and valves and connected it to the power head so that as the H2O left the power head it was split into the two sides, with valves to control the rate flow. The flow was then directed to pvc "arms" that had holes drilled in them. The result was a double sided kreisel style tank. It was a great idea and it DID work, but it didn't work... -Gluing the baffles into place leaves corners of "dead zones" which should be sealed off ENTIRELY. One of the four stayed air- tight, so it is possible. Our glue job left spaces under the baffles wide enough for all of the babies to get washed into those "dead zones." The dead babies and the food rotted in the "dead zones" and threw the water off right away. *Next time I'll frost the sealant on thick and really smooth it into place. -Aquarium sealant gives off acetic acid. If your tank doesn't have time to clear it out, your pH WILL DROP! -The current was WAY too strong! If we had gone with a smaller power head, we could have used more flexible tubing (a huge pain!) and provided a much lighter flow. Even with the valves in place, we had too much flow. -Next time I'm going to downsize to a single kreisel. The babies need more surface space than they had in that configuration. Having a walled off chamber to sink the power head still seems like a great place to keep a chunk of live rock and brittle stars to help with H2O quality, though! My biggest point here is that- ANYONE CAN FRANKENTANK!!! Save your old (working) stuff when you upgrade! I got that acrylic tank when I was 15. I'm 38 and still give it a new life every now and then. Be creative, save your old stuff and give it a try. If you fail, you have what you started with. If you succeed, maybe you'll be the one charging $500 for your cheapest creation!