Your fine to use it all the way through to ripening but the chitin response receptor is shutdown after 25 days into flower. You will still be feeding the biology, benefiting from sea animal aminos, calcium, phos, etc......Kraken is my favorite bottle of all the additives!! I foliar in veg and foliar in between BK sprays, then drench to week 4 flower. Thats the plan anyways, I will keep it in longer if I need to lower nitrogen aminos through second half of flower. Its a fire transplant shock reducer at 2.5 ml. W/ 5 ml Gaia!!