Canna Substra ?

I just recently went to shop looking for a new nute line and went with canna.problem is or might be that i was recommended substra after i told shop owner i was growing in soil less mix.am i missing somethimg or not because i believe cannas website says terra is for soil and soil less while substra is for run to waste systems.is this the right choice for promix and the like? thanks for any help

i have zero experience with hydro or any ponics other than good old pots so if im being dumb i blame it on my meds