excess nutes or slight nute burn
as most weed nutes are aimed at hps or 'heavy' light users nute consumption and water are higher
with Flouros the opposite is true
T5/T8's are a gentle volume light, you won't get blinded compared to an hps..lol
so avoid feeding and water so much
lift the pots before watering and think
cut back nutes by 25%
good luck