Quick Assessment?

Root bound, overfed and possibly magnesium deficient.

Re-pot them in to some fresh soil and add half a gram of a quality epsom salt (magnesium sulfate) per gallon to the water you're using. Use this water for the next 2-3 waterings.

Personally... I would get a neutral soil without nutrients. Pick up a bag of General Hydroponics MaxiBloom, GH pH Up powder, a bag of quality epsom salts and a pH drops kit. I also ONLY use reverse osmosis (r/o) water for growing the cleanest cannabis, with the most predictable pH results.

Transplant to the neutral soil in a bigger pot.

• Start with 6 grams of Maxibloom per gallon of water and stir/shake until dissolved
• Add pH Up powder, shake, test. You want 6.5 pH
• Add .5g/gal of Epsom Salt the first few waterings
• Water with nutrients the first day
• Use plain r/o water the next 2 waterings

Using tap water will have unpredictable effects on pH in the solution and in the root zone, as time passes. You'll have to learn how your particular tap water works on your own.

Dark green and crispy leaf tips is overfed. Lower leaves yellowing and dying out, progressing up the plant, is underfeeding. Each seed plant will have it's own 'perfect' amount of nutrients and you may find a few which are close enough to feed the same way. I use clones, so all the plants I'm flowering take the same feed. :)

Go Be Awesome! :D