Red algae and fluffy thing with hole??


New member
I have two questions. The first is that I have lots of red algae (I guess) on my LR. None of it is on the sand or the glass. It is not slimy or powdery and it doesn't wipe off. Some of it seems to be growing of the rock a little. Any ideas?

Another thing, I have 4 places now that are a little smaller than a dime that are kind of whitish gray and they appear to be sponge like. They all have one fairly good size hole in them. Any thoughts on these? I can not seem to take a decent picture of these things in my tank for some reason........

Thanks in advance for any advice!!


Premium Member
Okay...from the way you describe the "red algae" being that it isn't slimy and it isn't powdery, and, it doesn't "wipe off," it seems that it's coraline algae and that's something that you do want and so don't be concerned at all about it.

The thingees that have the "hole in them" are almost certainly tunicates, which are filter feeders and again, something that does benefit the overall health of your reef and not to worry about.


New member
is the algae hard and looks like its just the color of the rock changing almost? if so, its probably just a shade of coraline..theres a ton of dif. colors that it can come in. Or is it like a hair algae?

as for the others..i dont know. A pic would be great tho, even if its not really detailed, its something.