The talk about indoors plants dying from lack of light somehow brings back the first phrase of the book 'Genesis' (in the Bible). It has been known many thousands years ago that 'living things need light" and hence:  "...in the beginning darkness covered the world ... then ...let there be light..." and from that moment on lives prosper in the world. Life and Light! Still rage!

I wonder about the "white" deposits on some pots. I think they are "salt" marks. The question is what kind of salt? Calcium (eg. lime) salt would be OK. But Sodium salt can kill plants. Try painting the marks with vinegar... ;-)