Hi Jenny,
I am a big fan of Hydrotons too!
Just a word of warning: make sure your roots aren't touching the water reservoir. It is ok for the roots to go there themselves, I am just a bit concerned about your wicking distance, the container looks a bit short to me.
My rule of thumb- 1(diameter) : 1.25 (height of container approx.)
My other tip, to leave the reservoir empty after every watering (pour excess water out) for the first month or until new growth appear.
That is what works for me and my army of phals!
Happy growing & keep us posted!
