Please Help - What is this growing ?

Can someone please tell me what this is growing on my rock ? It look cottony. It just appeared a couple days ago, and now I see it on a second rock next some zoo's. I took these pictures right after my lights came off, so that you could see it before the corals opened way up and hid the stuff that is growing. What should I do with it? Corals on the rocks look great when they open. Parameters are all good in my tank. Ammonia and Nitrites are 0. Nitrates are 1. Phosphates are .1 or .2 (hard to tell which shade the color is). PH is 8.2 . Salinity 1.025 Temp is 82

Thanks! Pam

http://www.homebasedbusiness-usa.com/coral 1.jpg

http://www.homebasedbusiness-usa.com/coral 2.jpg

They look like sponges to me. I had a whole bunch of similar-looking ones growing all over my nano before i took it apart. I believe these are the sponges Rob speaks of in the refugium show. In the last part they talk about the cryptic zones - a low flow, dark fuge - encouraging these sponges to grow. They are very good to have. They help reduce nitrates and free-floating crud. I don't think they will harm corals but i am not sure about that. From what i gathered poking around with mine, they are pretty delicate and i think the corals can beat them off.

Nope, these sponges can overcome the corals. I have a sponge right now choking out my huge GSP colony. I'll have to grab a pic.

yup they are sponges, and as Renee said ... they can overgrow and suffocate the corals.

Ok... should I pluck them off the rock? I just pulled them all off of the rock with the mushroom. They came right off, and feel just like a wad of cotton.

Thanks!
Pam

Pam, I don't know how to remove them for sure but here is a :bump:

i would pull them all off of anything with a coral attached.

Yep, sponges. Just pluck 'em off and throw them away