Why did seedlings stop growing under near-optimum indoor conditions?

I've grown before, and my current conditions are exactly the same as the last successful grow. So, I have no idea where to even start looking for the solution to why
the babies have suddenly stopped growing. Both are in a soil/perlite mix, and have the set of coteyldon leaves and one very small set of regular leaves. Only about 3 days from sprout, so they should def have bigger leaves and maybe even the start of the second set. Temp is 79, humidity is 70%, sometimes 60%, i don't over or under water, especially not seedlings, no nutes, and (4) 23 watt cfl's 6500 K. of course. I use distilled gallon water. any ideas? this is especially frustrating considering i paid good money for the strains: northern lights, white berry, onyx.

how close are the lights to your ladies=)?!!

they are are close enough but not too close for heat stress issues. i had them at about 6 inches, than down to
3 inches, with no difference. While it might be more productive to get the lights even closer than 3 inches, at this
distance they would surely grow, maybe stretch, maybe closer than 3 inches would be better but still, I should have
seen more growth even at 3 inches.