i mean if you consider live rock to be covered in coraline algae and shrooms there are none, if you consider live rock to be covered in backteria thats exactly what this is...
about 200 lbs...i really need to weigh it to know for sure...i have a 33 gallon trash can filled to the top with rock and a few gallons of water fit in...the bottom 5 inches or so has LS...i will certainly weigh it depending on what you want...