@sanostyle9999 the bubbles go into what I call 'bubble storm' at least once every 24 hours. The bubble storm lasts approximately 45 minutes and produces a varied number of expansion and Vu items, depending on your experience level. It happens at different times during the day but will stay the same for as long as 5 days at a time before the time shifts. You need to continue to pop bubbles until you find it. Once you pop a bubble in your own city that yields an item, you need to continue popping for at least an hour. Bubbles appear approximately every 30 to 45 seconds. I used to get 12 to 15 items per storm. As I leveled up, the amounts changed and eventually went from twice a day to once a day. At my current level, I get 2 each of storage, Vu, and dozer parts once every 24 hour day. Originally, I recieved mountain and beach items as well. When I opened all of those sections, those items stopped being offered. The storm changes as you advance through the levels so be patient. At lower experience levels, the storm happens every 12 hours. So if you find it at 6 pm, it's gonna go off again at midnight.. Keep popping those bubbles, you will eventually get the hang of 'chasing the storm'. Good luck.