forminiferans?
red, like these?
http://www.saltwaterfish.com/vb/atta...1&d=1039904652
(pic from saltwaterfish.com)
I don't know much info about these guys other than, I've got them, they seem to come and go and are most often noticed in new tanks (as they are often the first bright thing to grow on live rock) they seem to stay small, cause no harm but may be sharp to the touch (more so the white branching variety I think)
edit: if all your stuff is dead (coral and rock), other than the sand I think it's probably not forminiferans .....is it a red slime? check out cyanobacteria/red slime
This is red slime:
http://www.saltwaterfish.com/vb/atta...1&d=1226540936
Your dead "live" rock will eventually become live again if you get a live, live rock to seed it with. (just put it in with your other rocks)
Hope that helps, I'm going to bed now
