!st reef is set up and I have a strange hitch-hiker

[Whiskey]

I'm really excited. I've been considering a reef for over a year and I finally filled my tank, 40 breeder, last night.
I purchased tons of stuff for this tank, lights, skimmer, pumps, overflow and a bunch of dead rock.
Today I went to the LFS and picked up some rubble and a couple of larger pieces of live rock for the new tank. I brought the pieces home, fired up the lights and giddily watched for signs of growth. I'm watching one of the new rock pieces when I notice something crawling along its surface.

A little spider!!! He's tiny, black and white, and he's got a little bubble on his belly to keep himself alive

S-SCUBA... Spider-SCUBA

Cheers,
Matt