m0useanswered grow question 3 years ago Hey I think this is a buildup.
Foxfarm nutrients run hot and if your using the suggested feedings from the bottle it maybe burning your plants. Autos also feed less then photoperiod plants and most bottles feed suggestions are meant for a heavy feeding photoperiod.
This is a good reference point for strength of feed for auto flowers. it requires you to use an TDS pen to find the solutions EC.
https://www.autoflower.net/forums/threads/med-man-method-feeding-chart-ppm-ec.47856/
I would just water them with ph water and nothing else for a few days/weeks. try not to add in anything else to the mix.
also let us know the ammounts your feeding with and how often in your diary.
fox farm trio lineup also uses grow big till just before the end in flower.
https://foxfarm.com/feeding-schedules
soil feeding schedule.
Good Luck and Happy Growing!