I run various algaes in mine. I've got several types of Caulerpa, Chaeto, some bronw egg noodle looking stuff, something Laurie sent me some time back (Cadium or somethign like that), etc., etc. I've also got some rubble piled up in areas (pod condos:D). I run lighting over it 24/7. I don;t currently have a sand bed in either one under the displays, but they are 'temp' setups until I can finish the room (nothing in the way now except overcomign being so freakin lazy...). I will run a sand bed, though-at least 4". Mine in the past have been low flow zones, with water feeding from a Tee from the display lines to one end (with a ball valve to reduce flow). I've always wanted to believe that the lower flow lets more settle out...