Blazin Skywalker F3

Had to transplant seedling outta plastic cups to 1 gallon pots due to the leaves turning brown and even though through research I could not figure out what the cause of it was I flushed each plant with distilled water a few times each and then after letting them dry out I transplanted into 1 gallon pots and again only gave water to I'm going to repeatedly do this until I can see if the cause of the brown was given too much news nutrients too soon as I said this is my first grow best way to learn is from mistakes other than that it seems to be going pretty good again any feedback is greatly appreciated "knowledge is power"