Depends how big your tank is, but I'd say its being a tad optimistic that its going to cycle in 7 days. I wouldn't bother with the chemical, go with water changes. If you haven't already read the article on the nitrogen cycle on this website. It explains that Ammonia(fish waste) gets converted by one type of bacteria into nitrites. Nitrites get converted by a second type of bacteria into Nitrates. Nitrates get removed with water changes/absorbed to a degree by plants. You're in the first stage of the cycle, and playing around with chemicals will likely just mess things up worse. Do you have fish in the tank yet? How many and what kind? Is it a brackish tank? Are you adding in marine salt already?