They are a little bit small. Have you added any more light yet or got the lights closer? I also noticed that you said you were on a 18/4 light schedule, was this a typo? You should be aiming for 18/6 or 20/4 or 24/0.

Also, it would be better for your plants if you had potted them with the soil level nearer the top of the pot.

Nice dex btw.