Yellow speckles on finger of one fan leaf?

Looks like residue from spraying and thirp damage. Best of luck on the grow.

You've got the start of powdery mildew and should address the problem soonest! It's easily fixed unless you let it go - it can spread rapidly and destroy your entire grow in no time. What you want to do is grab some damp paper towels and carefully wipe the leaves top and bottom. The damp paper towels will capture the spores and they are then easlily disposed of so they don't infect the rest of your grow. Then mix 1 part milk to 3 parts water and spray liberally while your grow lights are on. The type of milk (skim, 2%, whole, etc.) doesn’t matter. Wet both sides of leaves if possible. Powdery mildew is caused by too much humidity, too little airflow, poor ventilation and, rarely, leaf-to-leaf contact which traps moisture and doesn't let it evaporate... you're going to have to identify which thing(s) caused this and take steps to correct it! Since you're doing an outdoor grow, I'm at a loss to tell you how to correct any of these! I DO know you'll have to stay on top of the problem because the spores will go airborn and you may be fighting this for your entire grow. There ARE sprays you can buy (rather than use the home remedy of milk) and these might be your best bet... a product called GrowSafe is highly effective AND organic... https://www.amazon.com/Bio-Pesticide-All-Natural-Insecticide-Mildew-Non-Phytotoxic-Concentrate/dp/B07PH46H8K/ref=as_li_ss_tl?keywords=growsafe&qid=1562967531&s=gateway&sr=8-1&th=1&linkCode=sl1&tag=4200a7-20&linkId=ba7b1e87c8123892f5846fb7d221fe97&language=en_US Good luck - you're lucky already that you've caught this early!