Yep only used Canna once way back when lol. Used Plagron ever since and just find it simple to use and it just seems to work with my bitta filtered water. once all mixed I normally only have to adjust my PH by about 0.1 or max 0.3 down with maybe 3 drops of lemon juice.
Feeding in veg is one I've never really thought to much about. I simply wait like 2-3 weeks then start them up, feeding maybe every other watering. Sometimes less, I just try listening to my plants.
Anyway best of green to you my friend!