your plants have not stopped growing they are making resin glands
fun time
1 the led lights
what brand........do u have control over it ....
2 fox farm trio is only part of a much larger kit and program to fallow
https://www.amazon.com/FoxFarm-Dirty-Dozen-Starter-Kit/dp/B00KC8HWTM
that is the full kit
http://foxfarmfertilizer.com/images/pdf/soilenglish2015.pdf
that is the full feeding plan ........see how u mix all of them in
as for your watering u really should do this
water all the plants 1 time count the number of days it takes for the plants to droop from needing water ........fill up a 1 gallon water jug mix in your feed and see how much water it takes to really water the plant
so u now know how many days it takes for the plant to use all the water in the planter and how much to water/mix up feed for .........u want to water right before the droop so if your plant takes 3 days to use water u water every 2 and half) ...........u want the soil to go dry so the roots spread out and down looking for water taping into the soil plus if u keep the soil to wet it can lock out nitrogen absorption
but your trouble is simple .........the feed is not right u are not offering it the right builders .......it has resin builders so that is what it is doing u need to go to weight builders
beastie bloom in the feed plan
odds are it is a combo of micro nutrients and power (i see a dark green so means Nitrogen/Iron lvls are more then good) u need P and K right now