Soil, soilless, hydro, aero? If in 'dirt', is there anything added to the dirt (pre-ferted, blood meal, bone meal, guano, etc, or from the factory 'mystery chem amendments'?

All I can say is that your N:P ratio is very high. You want to get that nitrogen level much lower after the second week of budding, and phosphorous is necessary to put on bulk.
A booster such as pk13-14 is one way to go about doing that. But I am guessing that what you are using is not a canna-specific bloom fert. So switching to one of those, such as power flower, canna flores, big bloom, pure blend bloom, etc. would be the place to start.

Your micros look reasonable. So does the potassium level.

You might also consider doing a transplant into a medium that has had bone meal or a P rich guano added to it.
stinkyattic Reviewed by stinkyattic on . Need an advice on my nutes What to change? Day 27 of bud N-4.5% (2.4%-nitrate, 2.1 - ammonia) P2O5-4.5% K2O-6% B-0.01% Cu-0.009% Fe-0.034% Mn-0.018% Mo-0.001% Rating: 5