Finally I got it right with FertiActyl! Damn!!!
After I did 5ml/L, as advised by the Agro-cooperative clerk

, then later trying 0,5ml/L as per arithmetic calculations of correct dosage for a square meter (the bottle label states 2L to 5L per Acre). I finally reached the correct dosage of FertiActyl for my
very hungry NL5xH babe. So here it is:
Drum rolls sound!!
:hot:
...
:hot:
... Tcharan!!!
0,2ml/L every other feed
Ok... That's the same as saying 4ml/L of FishMix on every feed, which is what I was giving nowadays (and I still got yellowing leafs). Amazing product! Strong as crocodile sh!t! Just wished somebody else tried it before I did! Ahah!
How the plant survived when I first gave her 5ml/L of FertiActyl on her first months I have no idea! Had to be her strong genes! I remember I had to flush the hell out of her ass a morning before work because she was loosing her vitality so quickly. She was osmosing into the soil
props to JM for being my much needed help in those times! :thumbs::buds:
At the moment she's very happy and has had explosive growth since last LST and feeding on last Sunday. :thumbs: LST definitely helped, cause it allowed a lot more sun to enter into the canopy, and FertiActyl made the rest as she's greener than healthy green with lots and lots of new leafs!

It's not marketed for Canna but it sure is a pro product!