The water droplets won't cause burns. It's a myth.
I would look into mosaic virus. Apparently like 80% of strains or so have mosaic virus. Normally it's damage is negligible.
I hate to argue but, I am sure its from feeding them! Its the nutirents causing burns! Full strength fertilizers WILL burn leaves. You may be right pure water might not burn them . Anyone else care to share their thoughts or experiences? I am sure its not Mosaic virus! Way to stress this brother(plant n prosper) out! I think people mislabel all sorts of unknowns and deformities as Mosaic virus. Anyway sorry if i started an argument.