Yellowing leef and rusty spots

may need to add a touch of cal mag, coco and led both leech mg from the plant so often needs a top up as part of feeds. try a half strength maybe.

If i’m not wrong 1100ppm are 2200us , very very high ec if i’m right you can have nutrient burn

Looks like water is collecting on the leaves when you mist and creating light burn spots. dab the leafs dry every now and then should stop spreading

Those dots are absolutely calcium defiency 👍🌱

@gmslave runoff ph is at 6. Coco is pre buffered im told by Canna. I changed coco when i potted up. From a very cheap coco i double buffered myself. To Canna coco

Check your run off PH. if it's massively out then you made need to flush her out giving you a reset. Might be a nutrient lockout . Also you may need to add some calmag plus to your nute mix . I use around 0.75 ml/litre at your stage of growth . This helps keeping her healthy and gives you optimal nute uptake .