I'm feeling a little scared. I don't know what in the heck I am doing, and the warning labels on my chemicals have me scared to make a wrong move. Ok. It says I need PH Down, Calcium Hardness Increaser, Shock Plus, and a Chlorine Tab. I only have the tabs, and shock plus. So, I'm heading to Lowe's to get the rest, and also to get a floater for the chlorine tab. I'm a little confused as to in what order to add these, or do I have to wait to put them in seperately, or can I put them in back to back? Also, how long do we need to wait to swim after using these? The shock plus, says you can swim within 15 minutes, but not sure about the others? Thanks in advance for help.