You could try reversing the flow of the anti-matter injectors !

Out of 3 Phrag seedlings i bought about 2 years ago 2 grew pretty quickly.The other was a little reluctant , it would grow a little & then the bottom leaf would die.By the time a new growth started the old 1 was practically dead.
I tweaked the way it grew slightly & now it is spiking.
The only thing i did was to use a taller s/h pot.