Discosoma yellow growth

[greyhame]

Does anyone know what this yellow growth is on my discosoma? Is it safe to leave in the main tank?

 

[fishski13]

I thinks its a type of yellow encrusting sponge. I would say it is a good sign for health in the tank but sometimes they can grow too much in places that you dont want. Like they can grow and invade on coral space which can irritate and kill the coral.