When will my cycling start...saltwater help!?

I have a 75 gallon, that i just added 65 pounds of cured live rock to. It seems like its covered in nasty detrituss and dying algae and such, but its been in the tank since sunday, and there is no nitrite or ammonia readings. I havent checked nitrate, but there is no way my tank is almost cycled already. The rock was in a pre-existing tank, and i used live sand. when will my cycling start?