Hi! :) If the nutes were synthetic, maybe flushing would be an option. If organic, I would sit & wait.. maybe I'd check if I killed the pH of the soil in terms of dropping below 5..
The white spots may be bites.. I think that's normal for outdoors, and there are a lot of little helpers for that.
You want to use organic liquid fertilizers with every watering, as you are feeding the soil. I have no recommendation about how much, as I never heard of your nutes.
Have a greentastic grow!! :)