U need some calmag & possibly at this point u r under watering. when they start to flower, the watering needs change dramatically.
u should be using the "water by weight" method, where u water ur plants until it is coming out the drain holes, then set it down, & pick it up again to make a mental note of the weight of ur container. Then u water again when u lift ur container & it is light; u will easily be able to tell the difference. check ur ph, & make sure it is not to high, if so adjust accordingly, (usually with ph down) if so. also have u started bloom ferts with potassium in it? if not u will need to do so now that ur flowering.