Wedding Cake Autoflower - Barney's Farm

Seedlings are 7 days old today, 11 days from planting the seeds. They're showing significant above ground growth over the past couple of days. Notes from week one: 1. I managed to over feed the seedlings just a bit but I think I'm on track now. I'm using a nutrient schedule from growweedeasy.com but neglected to heed their watering schedule which calls for nutrients only every other watering (I was feeding every watering). Used a new TDS meter two days ago to check runoff against input and saw that PPMs in the runoff was greater than what I was putting in. MJ2 shows a bit of leaf tip discoloration likely due to my mistake and she also looks to be a tiny bit stunted compared to her sister. 2. I was probably over watering as well due to my unfamiliarity with growing in coco coir (is it wet or not?) I need to pay more attention to runoff volume. 3. Still learning how to stabilize temperature and humidity in their right ranges using the various controls I have over lights and fans and such. Our winter weather has been erratic, including a 60 degree change in temperature over a 24 hour period last week! I'm trying to keep the temperature in the 75 range and the humidity around 60.