I'm building an ecosystem right now, still in the planning phases...but it will be in a 10, or 20gallon tank. I have the acrylic dividers alread and I'm just going to put an actinic light running opposite the tank light in it. Cost wise it will only be about 100 bucks, probably use a mag pump because the rios are s#@t. I am setting up a 90 gallon with overflow, and a durso style stand pipe. I plan on documenting everything and will post some of it here.