I have first looked at my lfs, but haven't found anything as big as what I've seen in you guys pics, have looked online and not found anything the like. Where do you get these rocks from? My backyard is rockless, so...wait a minute, what about marble? Could I put marble rocks in my cichlid tank? Or do you think that it would mess up the ph or leach something harmful into the water? I just remembered we have a marble plant in town, maybe I could get something from there...