what is this red stuff spreading on my rock
globaldesigns Member Nov 24, 2008 #2 It is hard to tell, fuzzy pic, but I would say red coraline algae
saltyfish808 Member Nov 24, 2008 #6 i think this might be a little better of a picture....at least you can kind of see this stuff better
snakeblitz33 Well-Known Member Nov 24, 2008 #12 It could definately be a sponge. Nothing to worry about, and nothing to take special care of.
subielover Active Member Dec 5, 2008 #15 I have read that if a sponge comes in contact with air it will die.