I have grown in soil/coco mix and even if you amended it with neem cakes and alfalfa meal, it's benefits are long gone. Point and case with neem cakes in your soil your shouldn't have Bugs! Your plants are starving due to improper PH and bugs.
if you want to fix this "just winging it" will not do.
Catch some run off and check the pH, neem cake will naturally low your PH. What comes out the bottom of your pot needs to be around 6.0 ph, if not start flushing.
seeing that you will be flushing with water PH'ED at 6.2, mix 1 part H202 with 4 parts h20 to kill the fungus gnats as with combined with your pH problem their larvey will kill your plant by eating the roots, sticky trips catch flying adults but do nothing for the larvey and your neem cakes are not doing there job.
After you get your PH correct you need to routinely feed them, with Ph'ed water between 5.8-6.3 like they are in coco, not soil, still have answered my question about calmag?