Back to growing and troubles

Back in the saddle so to speak,haven't grown anything in 7 years and back then it was all autos. Decided to give photos a try when the growbug bit me this time. I have a super lemon haze and an apple crisp going in 7 gallon nursery pots and both are 8 weeks old. Growing under 4 4 foot tubes out of 8 on a t5 light panel,love my t5s! Soil is black gold with extra heartworm castings mixed in. Plants have had no feed other then worm castings,24" tall. Last week noticed some yellow leaf tips around top of plant on apple crisp. New growth seems to be pale on both plants and the super lemon Haze has developed leaf discoloration with a few brown spots. I water once a week with a gallon each per plant. Last night I decided to add feed so I used a tsp of dynagro and a tsp of calmag to the water and ph' Ed to 6.5. Doesn't seem to be alot of change today but I'd like to fix whatever's going on. I'm used to seeing the leaves up and praying everyday and this past week they're definitely not happy. Any suggestions would be appreciated. I'd like to start clipping clones but I won't until the girls are back to healthy.

The plants are mature, I see alternating nodes. Black gold is good soil, but you might want to up your P/K a little. Earthworm castings always supply micronutrients and N, however, the amount of P/K varies greatly between brands/suppliers.

Upping the p/ k should help with my leaf troubles correct? Thank you,much appreciated.

Sure looks like it, but nothing is 100%.