I had a small plant like this about a month ago. I flushed it with my typical nutrient solution at 1/4 strength, and then put it about 3" centered underneath a pair of H.O. T5's. They looked much better with the spots getting darker/greener within hours. A few days later (all the while watering with the same solution) they looked great. Although the spots never completely disappeared, they were effectively reduced to what I would call the equivalent of scars. Hope this helps!
Fuuze72 - If you have the money, try Neem oil. Your local hydro store should have some in stock. Otherwise I highly recommend getting some H2O2 (Hydrogen Peroxide) from just about any store. Mix a table spoon with a gallon of water. This solution is extremely useful for a ton of things. In this case spray the plants top to bottom, including underside of leaves. Repeat once a day until the gnats are gone. You can also replace some of the water in your reservoir, if doing hydro, with this solution. It will provide your roots with tons of oxygen, stimulating growth, get rid of and help protect and prevent mold, fungus, and root rot. Also works great as a foliar spray to rid of pests and insects (which you're about to find out lol) and if you don't have any insect issues, you can add 1/4 strength nutes and foliar feed. Also creates systemic resistance. Spray 'em with this regularly during veg and then a couple weeks before you're finished flowering hit 'em with it thoroughly right after your lights come on (so they have a good 12 hours to dry as well as grow). Now sit back and watch your trichomes grow and increase. Hope this helps!
