Advice + Help for diagnosing 16 day old seedlings?

Hello everyone! I'm looking for some advice for my seedlings. I planted these two sativa seeds at the same time 16 days ago and, although they have been growing okay, both seedlings have developed a yellow tint towards the center. On top of this, the seedling on the left is developing slower than the one on the right and has a yellow-spot on the tip of the true-leaf (as seen in the left leaf of the seconds photo).
The setup that I have is one 8.5W / 800 Lumen LED bulb that I keep spaced 1 inch over the plants, using regular tap-water in a spray bottle to water the plants 1-2 times per day (or whenever they look too dry). The medium I chose is a Seed-Starting potting mix.
Any advice or help that anyone can give me to keep these plants looking healthy and beautiful would be greatly appreciated! I hope that everyone has a great holiday season!
16_day_old.jpgYellow_tip_seedling.jpg
 
Top