was just a few, now a few short weeks later they are taking over the tank and getting really long

Can anyone tell me what this is? I think the brown with a green center is a coral of some kind. I'm not sure what the other creature is. It pops out of the brown circular shell from time to time.

not sure what these are but i have them all over my tank hiding in different spots....under rocks, under corals, under PHs

Wondering if anyone could help me ID this unknown white-clear "thing" on my LR I just noticed the other day. I'm not sure how long it's been there since it's toward the back of my tank where it's tough to see. I'm not sure if it's been growing at all either, but I'm going to keep an eye on it...

What kind of coral is this?:help:

Hello, I have a few things on my live rock that I would like to know what they are. If anyone can look at the attached pics and give me some ideas that would be great. The first pic, is the the one right in center of pic. It has an outer area that is pinkish with a green center. the second pic...

Hi i found today this slug like creature which is white and has got like flowers on its back and i was just wondering if anybody could tell me anything about it. thanks steven

Guys I hate to bother you. But could someone tell me if this is a sponge behind my feather duster? http://www.thereeftank.com/forums/picture.php?albumid=1244&pictureid=8773

Alright, was doing some Photo work in my 100 gal Prop tank, and noticed this guy. To be honest I thought it to be some sort of harry mushroom. Reason being he has been stationary for two weeks now on a Branching Goniopora. No movement and only when he started moving did he go from a typical...

Just found this and wondering what the heck it is. If you look you can see that it has a second flower like thing on the back side also. It acts like a feather duster retracting inside. At first I thought sponge, but do any sponges have retracting heads?

So I know that it is difficult to ID corals by picture only but maybe you have an idea. Info is it is not my coral it is a friends and he has no idea what it is. being that I am not a fan of having anything in my tank I don't know about so that I can provide proper care I am extending my...

Can anyone help me ID this thing? I think it has been in the tank for quite a while, but had not noticed it due to the way it blends it. It is not very large as you can tell from the button polyp in the backgroud and doesn't retract much if bothered. Thanks

does anyone know what this is? they are red flakes that are gathering up in one corner of my tank.

Are these aiptasia? should it be removed? Picture link: i791.photobucket.com/albums/yy197/maple55/Aiptasia.jpg