need help with 2 IDs

[naso140]

first 2 pics are of some kind of macro algae . ive always tried to find similar on the net with no luck. really would like to know more about it. the rest of the pics are of tubelike structures that dominate my sand bed. i googled tube worms for awhile with no luck. thing is my tank used to be wall to wall featherdusters when i first got it. part of me thinks its them tryin to come back but they just wont bloom lol. it looks just like the featherduster tubes.

 

[snakeblitz33]

You must have some really low flow areas in your tank. The first two pics as far as I can tell is a cryptic sponge. The second set of pics might be some kind of algae in the sand... the only reason I think that is because of the pattern that they are forming.... it looks like it's going with the flow around the rock. Either that or it could be some kind of sponges forming in the sandbed. Though, I'm kind of at a loss to be honest. Maybe someone else can join in the thread.

 

[geoj]

I think Snake has the fist one right cryptic sponge. The sand looks like Spaghetti worms or Hair worms.