Closet Grow- Week 5

Hey guys, planted these seeds on 2/5. A Cheese Haze X Widow seed I bought locally. Wondering if I could get a little insight as to any problems I may be facing shortly.. this is only my 2nd attempt of growing the magic herb, just wanna make sure I'm off to a good start. These plants are in a closet under 24 hr. flourescent light. In FF Ocean Forest soil, using FF Grow Big and Big Bloom for nutes. Feeding every other watering, generall water every 3 days. Haven't invested in a pH meter yet, so I'm not sure on the pH levels currently... Any suggestions on the best/easiest method to get situated with proper pH levels? Temperature stays right around 70 degrees. Just curious as to what these brown spots may be caused from? Thanks for the help guys!

very nice looking plants youve got!

possibly would want to transplant to a larger pot soon, especially before flowering

I want to say over fertilization.

Planning on transplanting to 3 gallon pots with Black Gold soil today. Going to try LST on one of the 4. Any comments on what may be causing this one plant of the 4 to have slender curled downward leaves? I just came home from work today and it looks much different than yesterday. Also.. the larger plant in the picture I picked up at a local shop for $8 because it was nute deprived and root bound, so I've given it some love and brought it back.. Any suggestions on pruning or topping or you think she's ready for the bloom room? Thanks guys!