I have no idea what sparkle conquest is, so I can't advise you there. I do know that if your stabilizer is 30-50 ppm (which I doubt--I'm one of those who absolutely distrusts test strips) and you put in 2 pounds of shock but now have zero chlorine, that you're probably fighting something in the water, and I'm guessing it's the sparkle conquest. So...you'll find that our advice here often differs much from the pool store's, and that people who try to follow advice from both us and the pool store end up frustrated. Because this is a busy time of year and we're struggling to keep up with posts from folks who follow the advice that we give, I'm going to ask you to choose one or the other--so we don't waste your time and energy trying to help clear up a pool with conflicting advice from other places.

Thanks

Janet