well this is the setup I'm CONSIDERING right now...I have available to be a 40gallon breeder and 20gallon long. And I know the 40 breeder may be a larger system for such tiny little guys...but I was hoping to have a really nice aquascaped tank, and be able to do just enough rock/barnacles to have a more open area as well so its not all crowded in there or anything,...and be able to make the 20long a sump and put a lot of rock down in there to help with filtration,etc. In the picture you can see my layout for equipment wise....and on the lighting, not sure if anyone has tried it....but I wondered about have a red lamp on the far left, an actinic in the middle, and daylight on the far right. Being in a 40, the picture is obviously not to scale, and itd probably not be a very big fixture/lamp....but I was thinking this way it would possibly give the octopus the effect of having a dark side where it would seem like they would be deeper or in a cave...then as they ventured right it'd be as if going out and about normally in a day....any thoughts? Then of course not shown in the picture is sealing in everything to make sure the octos do not get into the sump, or if they do, that they don't get into the return pump. Any suggestions, comments, ideas, hatred?