Okay cool.
Those plants- they look like you got them as clones? Often the low growth on clones looks scraggly at first as they adjust to life off the mom.
Flushing... I think there is a sticky on how to do that somewhere, or in the FAQs but basically, pour through 3x the volume of your pot using water adjusted to a correct pH (you check the runoff pH and then make a flush solution that will make it go to the correct SOIL pH when combined), then immediately water with your regular grow fert at half strength.
If new growth is already greening up, you might not even have to worry! Also if your grow fert has micros in it (it does I see), you can make a weak dilution to use as a foliar feed, just with everything, go easy...less is indeed more!