Discoloration of leaves

It's too small to take any nutrients yet. Auto's don't need any until the 3rd week & then only start with a quarter dose. What ph are you watering ?

the goal here is to fully remove the infection ** with amputation (left that part out)

once it is on the plant there is not treatment that gets rid of it... any promises as to such an end are lies and bullshit. it forms a mycelial network under the surface of teh plant.. removing it from the surface does not remove the infection. i would strongly suggest removingn this plant due to its size and age... it's fucking done for. it will spread to other plants. You could remove the infected parts and pray, too... but if you have more than a couple plants, i'd strongly suggest killing it at this point in time.. any remaining infection will be a fucking catastrophe in 2-3 weeks time. if you do keep it, amputate the leaf and spray the hell out of it with neem or h2o2+sufactant. repeat with h2o2 2x daily for a few days. neem you apply weekly and will only slow an existing infection down, it will never heal it. the goal here is to fully remove the infection and if spores collected elsewhere in meantime that the foliar sprays will prevent it from forming a new colony. i've used the anecdotal milk formula, the "cornell" formula (which i think is equivalent to green clean? and has absolutely nothign to do with cornell university.. they use the name to give the bullshit anecdotal remedy creedance, which it has none) and nearly every other suggestion out there... it's all bullshit that does not work. even extremely restricted antifungals are not very effective at holding back WPM. UVB is a viable option. vineyards have been using a new contraption blasting their plants with uvb after sunset for X minutes at a time and having great success avoiding WPM. again, once infected, it's there... all you can hope for is to slow it down... remove the diseased parts and hope for the best. Add dots and on / at end of edu, GD has a spam filter fucking with URLS.... extension psu edu powdery-mildew google "vineyards uvb mildew" and you'll see several articles talking about what i mentioned. --- some infections are inevitable given local enviornment... i've found that a bit more P makes plants more robust to diseases. it's even listed on teh leaf symptom chart i use but never connected the dots until i tried boosting P for different reasones.. whiel it won't help a plant that is infected, it may help make them avoid it in future. after a cuople years of consistent WPM issues, i've finally got a run in with zero problems... i was thinking about quitting growing weed it got so bad. now, there's hope. trust me on wpm.. just because it looks like it was cleaned off, it still is infected with fungus and you will inhale that shit into your lungs. (it will grow back twice as bad, too).. don't lie to yourself about this as it is a health concern. probably only a mild irritant but still unpleasant. you don't die from it at least. read that psu rundown.. they go over the facts and not popular anecdotes not tied to reality. neem oil or a horticulrual oil in vege is an excellent pre-emptive measure to take... it will not heal an infection. it will help prevent it from every getting a foothold (colony) on your plant which will inevitably explode into a mess.

Milk and water mix for white powdery mildew. Spray on when light goes out so it can dry, and not damage leaves. Lower humidity in grow area as well. Under 60 percent always. Will never have issues that way.