First outdoor grow, leaf issues - can you diagnose?

As you can see, some leaf death along the margin, with leaves primarily losing their green, fading to yellow and eventually dying.

Feeding Jacks Classic 20-20-20, approx 3 Tbsp/5 gals, every other water. Watering every 2-3 days, when 15 gal pot feels light. Soil is plain old MG w/ time release nutes, plants have been in for about a month. Soil was also watered very heavily during transplant. I can no longer see the time release fert balls at this point. I also added some Epsom salt to the mix, 3 tsp/5 gals the last feeding.

Any ideas? The leaf margins browning up makes me think over nuted, but the fading leaves makes me think an N deficiency...

Thanks in advance for any ideas.

From the description of your soil and nutes I would expect to see some downward clawed leaves (overfed), but I don't. So we know your plant has nitrogen yet is has a nitrogen deficiency look to it. This makes me think you could have a transport issue or be root bound. I can't see how big your plant is so don't know about being root bound. Is there a source of calcium in your soil or water?

Water is well water and I would expect it to have enough Ca. Plant might also be rootbound being its in the 15 gallon pot. It is approximately 3.5-4 ft tall. I can post full plant pics later on tonight (knew I shouldve snapped one ).

Thanks for the reply!

Epsom salt is best mixed with water and applied at the next watering...tho their is no (Mg) def. in those pics ..but standard nute burn due for a flush to my blog:
https://www.rollitup.org/Journal/Entry/flush-baby-flush.27513

vostok said:

Epsom salt is best mixed with water and applied at the next watering...tho their is no (Mg) def. in those pics ..but standard nute burn due for a flush to my blog:
https://www.rollitup.org/Journal/Entry/flush-baby-flush.27513

Click to expand...

Yep, ran fresh water through her at the last watering. The problem isn't getting worse, I've just been pushing her too hard. Will water with fresh water again here tonight and look to maybe fertilize the watering after that (with the nutes scaled back).