Mycelium appeared on top of soil

Just checked one of my plants today. And white fuzzy mold was growing on the top layer. I used a coco base/compost/worm castings with a couple of amendments...I read this this a good sign? I also use mycorrhizae. My plant looks very healthy.

yes, a good sign! Just watch the stem for any signs of discoloration. Its also a good idea to keep a close eye if youre in mid/late flower.

Yep. It's a good thing.