How to store distilled water without introducing impurities?

How can I store distilled water without introducing impurities? I'm going to be doing so electrical studies of pure water and ice and I need a way of keeping the water pure during the experiments. The water needs to remain relatively pure (I'm not yet entirely sure how relative yet), over at least the course of $1$ day. What is a good container that won't be leeching any salts or other chemicals into the water?


