So, a long long time ago (like a month ago) I stepped into the local pool supply looking for help getting started with my pool and the guy working the desk was nice enough, said I should get some chlorine tablets and a product called Perfect Weekly. He said this triple-action additive would help keep the pool chemistry and water nice and clear as long as I put three capfuls (about 1.5 cups) in weekly. Now, this stuff is $50/gal and I really haven't seen any mention of it around here. I feel like I've been duped. Is this really necessary?