I would switch your light schedule to 20/4. Plants do most of their growth in their sleep and photosynthesis during daylight. Your pH is also a wee bit high so I would drop it to about 5.9/ 6.1 . There are good graphs on the internet that explain pH and show what happens in either direction.
If you haven't already researched VPD ( Vapour-pressure deficit ) and how it relates to growing cannabis I highly recommend it as well as getting a PAR Meter and a Thermal temp laser gun like the Fluke 62 MAX to read the tops of your plants and be able to get the most efficiency from your lights.
keep up the great work!!
Also, I would start humidifying the room, humidity in the early stages of growth is very helpful. as the plants have itty bitty roots at this stage. The foliar intake helps get you through this slower stage of growth. If you don't have a humidifier make sure to get one and in the meantime use a bucket of water with no lid. It will passively increase the humidity.
If you have any possible questions just message me.
If you have the time check out my 200 LED 7000 Plants Diary, and stay tuned as I will be posting a Youtube tutorial series very soon.
Happy Growing!!
@HowGrowsIt, no problem! I am glad to help. Temperature and humidity control are vital throughout the whole grow. but they do change. So if you have any questions or are perplexed by something just message me. But for now lights on temps of anywhere from 79 - 84 F max and no more than 9 degrees less with lights off. The humidity you are good for the first few weeks of veg to go anywhere from 60-70%, Since they are autos be sure to pay attention to when you get decent bud sites forming then you will want to drop your humidity and not have it higher than 60%. Cannabis plants love heat and humidity it's the buds in flower that hate it.