I have a sand bed in my 55 fuge and really am interested in the Fiji mud. I was thinking of adding some right on top of my sand bed. Does this stuff have to cycle or anything? Or can you just add it in?
IMO you are better served by dividing your refuge in half syphon out the sand in one half and replace with about 4 inches of mud.
If you have not already, research Leng Sy’s eco system based on mud substrate
I did...I turned off the pumps and removed most of the water to a bucket for a little while. With one inch of water left...I added the mud and using a gloved hand for fear of bristle worms, I mixed it up with the existing sand, then waited for it to settle and very gently added my water full of copepods back in. Again wait for it to settle ...depends how careful you were adding the water back...then turn back on the pumps.