I have a 30 gal tank and it's been running for 1 1/2 yr. When the lights out at night there are these sewing tread like creature coming out from my live rock, they are about half to 1 1/2 inch long and about a couple of dozens of them. Does anybody know what are these? and are they bad for my tank?
Any input/advice is very much appriciated.
Any input/advice is very much appriciated.