Algae identification
 

Can anyone tell me what this is and whether it is to be feared?

http://members.shaw.ca/steveboer/119_1912.JPG

Looks like some red grape caulerpa. I occasionally notice some in my tank once in a while. Usually if your phosphates and nitrates are kept in check it won't become too much of a problem but if you can I would try to get rid of it. I had the green grape stuff before and it got way too out of hand. You would try to pull it out, but ripping it would leave its roots behind so it would always come back. It finally got to the point that I got rid of any rock with it.

I have that in my mantis tank. I think it adds some attractive red color the tank.

That stuff likes to grow in the the water intake cup of my skimmer. Or something like that...

I have some very good algae ID links ...HERE, hope they are of use to you.

Chuck