As a general rule the less stuff other than water that you add to your pool the better, if you follow the TFP methodology those things tend to be:
1, Chlorine which breaks down over time and outgases into the air
2, CYA Stabilizer, which for all practical purposes does not break down and stays in your water, it protects the Chlorine from sunlight and buffers its effect, but also must be maintained in a certain ratio with the Chlorine this is why it is important to know how much you have, and not continue to add things like Stabilized Chlorine products that cause it to build up.
3, Muriatic Acid, which contains only Hydrogen and Chlorine, the Hydrogen becomes an additional ion in the water that is already made up of Hydrogen and Oxygen and the Chlorine outgases with the rest of the Chlorine (well that is the simple explanation)
4, Salt if you have a Salt water chlorine generator, which is Sodium Chloride, which the SWG uses to create Chlorine by passing an electrical current through the saltwater, this again gives us Chlorine and a Sodium ion
.... get the trend? Mimimize those things that will stay in the water, no complex detergents, no Phosfree, no snake oil products, mostly just straight forward simple chemicals, preferably those that add little other than the components of water or Chlorine, or other things that will either outgas or get caught by the filter.
Ike