white fog from brittle starfish

[Radioaktivni]

Hallo to all, I have a strange behavior in the aquarium starfish... During the day a lot of them came out of stones and emitted white fog.
I will try to attach video.
And today water is white and I have in sump a lot of foam...
I hope someone knows what is going on.
I can't post video, I do not know why...
There is two photos.

 

[_Alex_]

Sounds like spawning.

 

[reef lover]

Yup agreed spawning....

 

[tonto95]

Sounds like they are spawning. The tank must be doing really well for them to be behaving like this.