The name "spaghetti worm" predates the reef aquarium hobby by several decades. I first heard the term in my first marine ecology class at Woods Hole in 1969, and I am sure it wasn’t coined then and there. In all cases, prior to recent usage in the reef hobby, this term refers to the worms in the family Terebellidae. The terebellids live in tubes in sediments, rocks, or debris, and do not normally leave the tubes. The only parts of the worm visible on the substrate surface are typically the white to slightly pinkish feeding tentacles elaborated from the head. The tentacles from larger worms are about the same size and dimensions as angel hair pasta, and give these animals their common name. The feeding tentacles extend some distance from the burrow and collect small food particles in a stream of mucus which is moved along by microscopic cilia found in a gutter on tentacle’s surface. Arising from the head region are also two to four pairs of bushy, bright red gills. These are not generally visible outside the tube, but when the animal is feeding with the tentacles extended, the gills are located just below the opening of the tube.
so it sounds like there is a bigger worm we cannot see and the spagetti like ones we do are the tentacles at feeding time?
here is the link http://www.reefkeeping.com/issues/2002-06/rs/index.php
I am going to read more maybe they will say how to kill it!
Those with the feeding tentacles send them up to the surface where they roam over the surface in search of food.
>this kind of matches your description of what they are doing at night while you sleep
much more reasearch needed , coffee