This is the photo. They are growing fast and spreading all over my tank super fast hitch hiked from on a coral I got last week.
I am worried they can sting. They are little tubes with what looks like a polyp for a head with little hairs that pop out from the sides. They get fat too like they are filling up with water.
I am scared they are "DIGITATE HYDROIDS" which I hear sting.
My photo of this <a href="https://www.aquariumadvice.com/attachments/photobucket/img_864867_0_5811f47b1b96330dc3e1ab177e79f6ef.jpg" >CLICK FOR PHOTO</a>.