Dark spot on live rock?

Ok so I have fully cured live rock in my brand new 90gal tank. it has been set up for a little over a week. I cleaned the rocks very well removing any loose stuff prior to placing it in the tank. The tank doesn't have a smell at all and 98% of the rocks look great. Nice and brown and green and red stuff. However, there is one rock that has a black spot on it, and I figured it was dying, so I pushed on it with my finger and dislodged it, and removed it from the tank. some other parts were looking a little black, but didnt come loose. What should I do to help this problem, or is it a problem? and also these little pieces of what look like chopped jelly fish fell of a few of the rocks. for the most part the rocks are really pretty, i'm just not sure if its just cuz the tank is new or what. I heard that you should vacuum the sand to remove the stuff that falls off the rocks, and I tried. It didnt work out. the sand was being sucked up, so I pinched the hose a little, and then even when the hose wasn't being pinched, it wasn't strong enough to pick up the stuff! UGHHH! and my tank is too tall for me to reach the bottom, and be able to see what I'm doing. so I have no idea what to do. will it just go away on its own, or will my new fish clean it up or what?

 

I wouldn't be too worried about it whilst its in the cycle, although a picture could help us ID what it is for you

Most peoples policy I think is 'if in doubt, take it out' but mine is 'if you're not sure, let it live some more' << I just totally made the rhyme up just then!
But I don't like to take stuff out incase its not a pest, and it could turn out to be something great to your tank

 

ok. I'll take some pictures of it. I'll post them soon.

 

I noticed on tank setup that you posted that your PH is at 7.6? you should be between 8.0 and 8.4 This will have an impact on rock as die off accurs.

 

I noticed on tank setup that you posted that your PH is at 7.6? you should be between 8.0 and 8.4 This will have an impact on rock as die off accurs.

+1 agree

 

I didnt have a salt tank when I set that thing up. that's my freshwater. I guess I need to update things....I just never feel like it

 

So what's your PH at know?

 

good eyes. I didn't notice that

 

so I can't figure out how to post pictures

 

I don't know what other people do, but I upload them onto photobucket first, then use the IMG code