White spots are limescale from tap water. Descale and they clear.
Cloudy bottles? White spots? It's limescale from your tap water. One tablet, one Deep Clean, one rinse cycle, and it is gone. See the descaling article for the full protocol.
Hardness varies from home to home, even within the same city. If white spots keep coming back sooner than a month, descale every 2 weeks instead.
If you switch to distilled or reverse osmosis water for the tank, you will not need to descale at all. Jug and carbon filters improve taste but do not remove the minerals that cause limescale, so they will not stop white spots.