Hmm, I'd think by now that the tank would be cycled. Maybe not though, what are your maintenance routines like? Could it be that the new water you added was cloudy out of the tap? Sometimes I get that with my tap water, but it's pretty rare. It should subside in a day or so if thats the case.
What size tank do you have and what is the
bio-load (how many fish)? Did you change out all of the filter media along with the
activated carbon? What's kind of filter are you running? Details, details, please.