There auto seeds do they look ok for 17 days old?.
Is there a chance I shocked them when I changed tent and moved them under a 600watt hps bulb rather than a cfl bulbs?.
I'm only 5 weeks into my first grow.
I over fed mine (1st 5 days) and caused Nute burn - it shocked them and stunted the growth so they're more like 3/4 weeks old by size.
In your plants I see none of the signs of shock that I saw in my own.
Yours look very healthy.
If you can afford it you could add Rhizotonic to their feed....?
It soothes shocked roots and is supposed to be effective but it's not cheap.
Whatever you do you can only carry on. And I predict that those plants will start to do some serious growing over the next 14 days.
Slow and steady, my friend.