I believe that chlorine will naturally escape off overnight. If you use a campden tablet or filter the water first, you should not have a problem. At certain levels, the S/P metabisulfate will create a 'fart-like' flavor in your beer. I was using it for O2 control and the low-O2 guys were playing with the amounts .. 100ppm, 50ppm, 25ppm, 12.5ppm .. I could still taste it so I stopped using it. But getting the chlorine out of your water prior to brewday should be easy. Just get your volume of water ready the day before you brew and it should gas off. If that's not handy, a carbon block water filter should work. I filter all of my water through a water filter either the day before or the day of brewing because my source water smells and tastes like a public pool.