Looking good man. I would try to get that humidity a bit higher, Cannabis plants LOVE heat and humidity. It is the buds that do not like it, Veg the plants love humidity in the air to supplement the roots with some foliar feeding. Look into vapor pressure deficit and how it relates to growing cannabis. If you do not have them already get yourself a PAR meter and a thermal temp gun to help read the tops of your plants. It will really help you get the most out of your equipment and maximize the potential of your lights. Please feel free to follow my profile & if you have any questions never hesitate to ask. Happy growing friend.
@LegacyMarketFarm, thanks! I purposefully have had the VPD higher for a while to help the pot dry out quicker from the overwatering issues. Lowering the VPD back closer to 1.5 now.
Nice job, maybe try a spray bottle for your plant the dust from the sand can slow down the plants process of photosynthesis, otherwise looks great wish you the best of luck.