Anyone would work, but for sanity sake and ease I'd go the bio-bizz range, it's organic as well. If you want to experiment then you can try the hortimix that they make as well, but you'll need to ensure you have a ec/tds and ph pen.Sorry, forgot to reply. The leca was at the bottom of my pots for drainage.
I haven't tested the water, just using municipal water.
If I go the promix organic medium in pots, which of the nutrients you mentioned would you recommend?