high everyone, hope everyone's feeling great!

just started growing. first few harvests were great: thick, heavy buds; now buds are "stringy" and skimpy. could it be humidity? also just changed fertilizer. was using powder bird guano; now using budswel organic tea, which also has bird guano, so I can't see how that could make a difference, or could it?
Also, anyone have any review or opinion on
LED lights?,
any help would be greatly appreciated,
God bless,and the blessing of the saints with you all