Is this a worm? or spider web algae, it formed overnight (i check every spot in my tank before i turn off the lights)

[reefo420]

Is this a worm? or spider web algae, it formed overnight (i check every spot in my tank before i turn off the lights) and it wasn't there yesterday
also is this just a feather duster worm or something else? looks bigger than the others

 

[vetteguy53081]

Is this a worm? or spider web algae, it formed overnight (i check every spot in my tank before i turn off the lights) and it wasn't there yesterday
also is this just a feather duster worm or something else? looks bigger than the others

These are colonial hydroids and a mass of them
Best is to take rock out….. scrape every stem off at the base and discard
Other option is to direct water flow towards them- not at them and they will soon starve,,,,,, but I prefer manual removal