run off ... was very acidic. What does acidic soil do?
As Charles said about lockout, but I'd like to add that you'll probably notice it in a severe way 2-3 weeks into flower. Based upon the photos, I'm thinking another week. It will look like a cal/mag deficiency, and eventually phosphorus deficient[1].
What was your runoff?
You can begin cultivating dolomite lime into your soil. About a tsp spread onto the soil, and use a kitchen fork to rake it into the soil (but avoid tearing up roots). You may want to do this 2-4 more times depending on the size of your pot and how acidic your soil is (water between each application).
You should also prepare yourself for foliar feeding. That's a good way to supply the plant with nutrients when the roots can't do their job. If/when you have cal/mag deficiency, you'll want to use epsom salt, about 1/4 tsp in a pint sprayer. (You can also use 1/2 strength bloom nutes. Might not be bad to do that now.). Try to spray the underside of the leaves, and check your local stores for some "surfactant" or wetting agent (causes the spray to spread instead of bead and drip off). Be careful not to put the plants under your LED while there is water on the surface, it can cause light burn. And, be careful getting your buds wet because it can cause mold. (You have to weigh the risk of losing the plant against the risk of mold.).
I'm fighting an acidic soil problem right now. After 3 weeks the soil is just beginning to return to a reasonable ph. I am running a separate experiment with dolomite lime and it has shown that it takes 10 days to begin to have a small (but noticeable) effect on ph. I also watered in some hydrated lime 3-4 times. (That's very strong and toxic stuff. It shouldn't be used except in an emergency.). And, watered with 7.2 water when not watering with hydrated lime (which was nearer 10.0-11.0).
The combination of those three things seems to have brought me back to a healthy range. But, it took 3 weeks. My point is: start working on it now because when it goes bad (a little more into flower?) it goes
really bad. My plant was extremely healthy, the bushiest I'd had yet. It deteriorated very quickly. I had no idea I had acidic soil until it went bad (because I wasn't checking runoff ph. I assumed it was ok because the plant looked so good.).
[1] Photos of deficiencies:
http://growweedeasy.com/marijuana-symptoms-pictures
