Your buds appear to be pretty firm.Have they started swelling up?You know about checking trichs,but when getting toward end,you'll see your buds swell up and get heavier.Im guessing 3 wks tops
Since they come ph balnced.you need to lower the rocks ph down to 5.8 or so like legal said.I soak mine overnight in water ph'd to 4.2 and the rocks are right where you want em.without ph'ing your rocks,your ph will rollercoaster.