What are these white things?

[rob020880]

Hello,

I have all of these little white things inside of my overflow and inside my sump, and skimmer. They seem to attach to the acrylic wall and grow. I have been keeping my refugium light on 24/7 can this be a contributing factor? If so why are they in my overflow?

What are they? Are they harmful, and how can I eleminate them?

[nevolved]

Scypha Sponges

http://images.google.com/images?hl=en&resnum=0&q=Scypha+sponges&um=1&ie=UTF-8&sa=N&tab=wi

[nevolved]

They are filter feeders, not detrimental.

[rob020880]

Is there a way to get rid of them?