little puffs of something coming out of rock, what is it

[napydred]

hey, so i bought some live rock on friday, today i have noticed little explosions of what looks like dust (spores?) out of a certain area of the rock, this has happened a few times in the past half hour, any ideas what is puffing these little spores or whatever out? its coming out of the rock,

 

[Devilishturtles]

Sounds like you have something in there, likely a crab or worm. Could also be some sort of mussel or clam closing.

 

[lando]

Sea squirt or tunicate?

 

[napydred]

i've noticed some worm like things that have long grey/white tubes and come out the end lookin like feathery mushroom or dandelions, a few other little things, i must say there seems to be a lot of living stuff in and on the rock itself, i guess i know why they call it live rock now, thx for help so far, BTW i moved my hydrometer to the other side of the tank away from the filter/pump and the SG went up to almost in the red, i got some distilled water and was gonna put some clean water in to buffer out the SG, anyone disagree with this idea to bring the SG down?

 

[Devilishturtles]

No, sounds like your hydrometer is pretty...malcuntioning. SG doesn't change throughout the tank, unless you just did a water change or something immediatley beforehand?

 

[roka64]

I would invest in a refractometer. I have found the hydro to be difficult to get a decent reading. I believe they should be about 5inches below the surface of the water, away from the current. I also had problems trying to clean it when algae got in there, and I am sure that threw off the readings even more.
You could do a PWC to get the salinity down. Just make it lower than the tank's.