Thanks Pin that is interesting, I use Canna products, but only 200 ppm A&B in veg and 400 in bloom. Working well for me.
I used the H3ads formula for GH Micro and Bloom in coco when I was doing Hempys, got burn every grow,
I backed off the 6/9 + 1 g Epsom and went with 4/6 + 1 g Epsom and it worked better, still got lots of tip burn. Ended up at a 2/5 + the gram of mag and some Cal/mag and it worked well.
When I first began using Canna I was using their recommended rates and got burn. Since going to the lower rates no prob at all.
Now at those numbers I add GH Cal/Magic because at 200 ppm extra Calicum is needed to make up what your not getting at Cannas full rate. There is only 44 ppm of Cal at that rate and plants need around 150 ppm of cal, so I make up the difference with Cal/Magic.
That was probably too much info but it works with the nute program I am using.
GR