Curling Leaves on Northern Lights

Might be signs of "overwatering" which is pretty much because of no proper drainage, try irrigating around quarter of the size of the pot which for you is 0.5 gallon or 1.9-2 liters of solution and make sure that at least third (1/3) of the irrigation amount comes out as runoff and let the top 5cm of the grow medium to dry before watering again *and try not to dry the medium completely*. Also keep a close eye on the tips of leaves at the bottom of your plants since the foliage is very dark indicating early Nitrogen (N) toxicity, if the tips start to "burn" and develop chlorosis reduce the fertilizing with nitrogen to about half and slowly increase it as the plant heals and matures. Overall plants look great!! Good job! Happy growing :)