White Slime

[kien]

Originally Posted by RenHoek104

I also got the same diagnostic from my friend. He told me not to worry and it's probably just sponges. However, how did they come to be?
Ren

They hitch hike quite easily on live rock. Often times they are there but you just can't see them at first. They filter feed and take up nutrients in the water so if all of a sudden you start to see an explosive growth in a sponge colony (kinda like what you're seeing), it could be because it has found an abundance of nutrients in the water.