I too hade spot on some leaves like you are describing and I was spraying them with light mist, that when the spots started to appear but I did not relize this I thought they weren't getting enough moisture and contiuned spraying the leaves thinking it would help it got worse, after losing several leaves to this I decided to quit spraying and I has not returned since. So if you are spraying your plants stop. As the previouses person posted it will create hot spot on your leaves and could evently kill your plant. Do not let water hit your leaves it will burn them. Good Luck on your grow and if this is your problem the damaged leaves will not get better but it will kill your plant and spread to other leaves unless water hit them. Bizzy