Mephisto Sour Stomper (Indoor)

I’ve been keeping the soil moist by spraying it with 12oz of water around the edges every few days, trying to avoid the base of the stem. I lowered the tent humidity from 68% to 62% & have slowly been increasing the light intensity every few days. The light is 15” from plants, currently at 37.5% intensity (TSL2000 - 300w). I noticed a bit of tip curling on Plant 2 around Day 11-12 (see photo of Plant 2: Day 13), I’m staying vigilant, but have not taken any course of action yet. I am in 5 gallons fabric pots, using Happy Frog Soil. I haven’t used any nutrients and have been pretty careful about over-watering. Any tips or ideas on the issue I’m experiencing would be appreciated!