I posted a couple of weeks ago showing these string like things on my zoas. I blew them off and it seemed like the zoas came back good as new. But now, they seem to be coming back stronger than ever. Does anyone know what these are and why they seem to be all over my tank. They don't seem to bother any of the other corals but they are on all the rocks.
Looking at your picture it looks like you have spinoid worms , the best way to battle them is with a tooth brush and a wooden shishcabob stick . they can over take corals fast they are easier to battle on the rocks ,
they strive on food waist it is very possible you have a build up of left over food on your rocks , blowing them off daily helps rid build up .
what ever you do don't let them reach the sand . once they get into the sand the spread like wildfire . I had so many it looked like I had a white carpet .
I removed each and every rock and scrubbed them with a peroxide mix rinsing before returning them to the tank . I replaced my sand 3 X in less than a month , this is how fast they reproduce these things don't give up easy .
Finally I just had it thought I lost the battle . I removed all my fish put them in a spare I had , Drained every drop of water refilled with clean water every day for 2 weeks I blew off the rocks drained half the water refilled daily .
after the 2 weeks I drained the tank one more time removed every bit of the sand replaced with new sand filled back up put fish back in .
the first 3 days I was getting nervous again I was seeing these worms again on my rocks . but by the next day they were gone .
this is how it looked before I finally won that hard battle
Remember don't let them get to the sand they are easier to fight on the rocks. you really don't want to go through what I did . it in no means was a fun ordeal so blow off rocks daily it really makes the difference . it keeps your corals happy and those annoying worms away .