Post some stats for the tank, how long has it been up, what kind of filtration, what do you test the water for and what have the tests been reading.
i just added like 40 lbs of live rock.. my water has been smelling differently since than as well.
Adding 40lbs of LR
at once could cause an ammonia spike, have you been checking ammonia. Running the skimmer will help. Does your skimmer pull much crap out of the water? Doing a water change never hurts. Do about 20% of the tank volume every month or even 10% once a week. But most important, test your pH, ammonia, nitrite and post the results.