First Grow - Jumping into the Deep End

I may have had the light too close to start, I had it about 26 inches away @ 80%, was seeing LUX=17k. Backed it up and went back down to 50%, lux now reading around 9k. Demeter is showing brown spots on the leaves, not sure if this is due to the light being too close, or possibly phosphate deficiency. Kini is out growing everyone else. Alice & Lorraine are 6 days behind the other two, but are trying to catch up. All plants now have nice white roots down into the bucket. Just changed all the buckets last night with a minimum nutrient solution. TDS=260, pH=5.8. Moved light further away and turned down to 9k LUX.