that kind of reminds me of this pet store here. they have the dirtiest looking tanks, but their fish always survied, and were healthy. too bad they dont have SW stuff. if they look healthy i would by from them. from the looks of that one pic with the tank that has the cyano along the sand, their DSB isnt working properly. i see a black streak of sand along the bottom. the cyano is probably feeding on the nitrates from the DSB.