Base rock from the beach

[skiguy411]

I am at a beach in North Carolina right now. Yesterday when the tide was low, I noticed some really nice rocks that I thought I could use as base rock for my 30 gal tank. So I took a couple and left them on the shore to get later.

Is there anything I should do with these rocks before placing them in the tank (which is about 3 hours away)? I suppose I would need to cure them.

Also I found some really neat yellow seaweed-like stuff attached to some rocks. It kind of looks this stuff but yellow and not quite as full. Does anyone know what it might be? Could I use it?