<span class="link_user">@wolfvb</span>, Hi, thanks first of all. My medium was BioBizz Light Mix, fed the first two-thirds with Canna and the last third with BioBizz. I have to say the Canna root fertilizer is really great and completely organic. I looked at your diaries; you could use larger pots. Mine was in 15L and try to make sure the main root could grow straight down without any solid pieces getting in the way.