How much and how often do you use the potassium silicate?Potassium Sulphate or Potassium Silicate works really well. I use both.
The silicate is nice because Silica is definatey something you want to be feeding your plants throughout it's life cycle.
Then the Sulphate for a serious potassium boost. I use this at around 30-45g per a plant every week from week 4 of flower. I do have a pretty dialed in organic system so you might want to start a bit lower but yeah works perfectly for me.