My husband and I used to own rental properties that were leased to Colorado College students. When we purchased our first college rental, we thought there must have been a water leak to have caused the extensive brown ‘water spots’ on the ceiling of the living room. After purchasing our fifth college rental with the same ‘water spots’ on the ceiling as the previous four, we finally figured out that the ‘water spots’ are actually the result of what happens during a college party when numerous college students shake up bottles of beer and then open them.