The only two you really have to watch is chlorine and muratic acid.........they need about 15 mins in between them as they do not play together well. They should also be stored away from each other. Your muratic acid should be stored in a well vented area away from metal as the fumes can cause rust.
Kim, your reply made me think of something. Muriatic acid is poured in front of a return. If you have a SWG making chlorine at the same time will this be bad news? Or is the chlorine concentration so low coming out of the return it doesn't matter? Ive been adding muriatic acid and not noticed a problem but not sure my SWG was producing chlorine at the same time.