I am in the same boat. I am trying to determine whether the 75g goes BB or SSB. I like the look of sand, but the ease of cleaning in a BB. My tank will have a CL running either a Snapper or Dart pump and sand storms are my other concern. My question is, are the sand storms mainly around where the outlets are for the pumps or are they everywhere? And once the initial storm is over, meaning the sand has been moved by the current, does it still continue beyond just what sand falls back into the water path? I do like the idea of the BB in the back and sand in the front. Here is a rack I built to stack my LR on so that it would be open underneath for fish to swim not have to have so much base rock.
What do you think about lining the inside of the legs on the edge with acrylic and then the sand would just be on the exterior of the LR aquascape. Then under the two islands, would be bare bottom and that is where the exits of the CL would be, coming in and turning down via 90 directed right onto the bottom. That way it would pretty much blow detritus and stuff out from under the piles into the sand where snails, stars and such could get to it. Also, that would mean I only have to vacuum and stir the exposed sand. Make sense? I know a littlesand would end up under the piles, but should be kept blown towards the front. Another option is instead of a 90, I use a T and the bottom blows the bottom glass and the top have a section of locline on it that can be directed to other areas.