5 is too low for ph in soil. and my experience with foxfarms soil is that its nuclear hot and has a half life of about 6 months. my runoff is at 6.5 and usually is especially new soil. the ppm tho is well over 2k and stays high. the plants i have now were started in it from germination. i still dont need to add much more than a little calmag and now that theyre flowering ive added a tiny bit of big bloom and tiger bloom maybe at a 10-20% of the suggested ratio. the runoff is still above 2k so no need to add main ferts.
try flushing them, and only give them water and maybe calmag for a bit to see if it clears up then you can readjust your feeding schedule. id get rid of the drops for ph and get a meter that will also give you ppm.

oh and gold star for the day for having the form filled out!