Help id please

[greggreenberg]

This stuff looks alive. It moved around and grabs food on the sand bed. What is it is it bad and if so how do I get rid of it. Looks like brown hair algie but not sure.

alt="" />

alt="" />

 

[spike]

looks like a spaghetti worm.

 

[greggreenberg]

Are they bad ?

 

[camellia]

Here is some info

 

[kilralpine]

Just posted on this about 2 weeks ago as well: