Do you let new water sit before you put it in the fish tank?

I do. My belief is that adding any kind of chemical to the water in a tank is basically the same as adding chemicals to the air I breath. I would not appreciate it. All I need is clean air and all fish need is clean water. The chlorine added to reticulated systems will evaporate off given time, so I let top up water wait overnight in buckets before using it.