Several question: 1. For those of you using the cube type PVC design, is the tubing completely closed? I guess the air trapped inside will help with flotation, but it won't help so much that the whole thing floats on top, will it? 2. Is shade a necessary addition? 3. The area that I would put my fish cage in is currently not aerated. Could one of these cheap, little, floating, solar powered aerator, fountain things be tethered to it to add some circulation?
