What the heck is this??!!
 

It is bright red (quite pretty actually), and about an inch across. Never noticed it until a couple days ago, as it is partially hidden behind a rock in the back of my tank. I thought maybe a sponge, but it moves a bit with the water currents unlike some other sponges (not red) that I do have. Or some kind of macro algae?

http://i1304.photobucket.com/albums/...psed379d9e.jpg

I am guessing it is Peyssonnelia squamaria. Some type Chloroplast, so yes some algea. Its pretty cool looking, I remembers seeing the same thing at Wais.

http://en.wikipedia.org/wiki/Chloroplast

Yeah, I guess that is possible. Doesn't quite match the shape and colour, but I haven't found any closer resemblance.

Its colourful though
I guess the tang doesn't eat it

That's a red macro algae known as Predaea with gelatinous thalli . I should have a frag last year send to me from a guy at Edmonton but the plant didn't survive due to cold weather & poor packing. If you don't want it, I'll love to purchase or trade from you.

No,... not yet. Yeah, it is really bright red. If it was a coral, would probably be worth a fortune...LOL.

Will see how it grows. Like I said, first saw it only a couple days ago. Hope it is not some bad pest, though, that will overrun my tank.

I googled that, and yes, that could be it. Except mine is much brighter red than the internet pics I saw.

So, are you telling me this is worth something?...LOL

I am going to let it grow out a bit, and see what it looks like. Keep in touch.

I look forward to that so that I can have a frag from you.

So, how do I frag something like that? Just slice off a piece? How do I stick it to a new rock?

You simply use a sharp blade to slice off a small pc. ( approx. 1/4 or 1/5 from the whole ) either glue directly to a rubble ( not always workable ) or to place it inside a small clear plastic container without cap together with a rubble inside for it to anchor naturally and to place the algae or holder to a position without strong flow and intense light. The new frag will take a week more or over a month to be noticeable any growth depends on enough of nutrients obtained from the existing water column. HTH