First grow Lemon Cherry Cookies

If the specified calmag amount is correct, that would definitely be way too high. But I can also imagine that it's due to the website. The leaf tips would be totally burned and dark green leaf surfaces. Hashy is definitely right that a complete nutrient solution with flowering fertilizer + calmag at pH 6.5-7.0 should be best. Once the magnesium deficiency is gone, pH 6.0-6.5. For water, maybe start with a Brita filter; an osmosis system is always recommended in the long run. With tap water, always use a bit less than specified for the nutrient concentrations, as the water has a high EC value depending on where you live. A good starting value would be EC 0.2-0.3; for me, it's, for example, 0.7.

Oh wow, I’m with Hashy on the calcium amount. Maybe you listed the amount you’re giving incorrectly? 113 ml per gallon. If this is actually what you have given, that’s an insane amount. Something closer to 3-5 ml per gallon would be more like it. 113 is probably more than a plant would want in its whole life lol

Also if your giving the plant the amount of calmag your diary states then your giving it way way to much.

The package says to fertilize every second watering. I would go down to 0.75 per liter, they're already showing signs of over-fertilization. Maybe a bit of calcium too. ✌️

I've used these powders. They are very potent. Also, you can't go by Grams per L. Depending if your water is hard etc. Also, you are PH'in these solutions right. Ph from these powders are in mid-low 6, for my water anyways. Start adding higher PK. But looks like it's ph related. You are flushing out that coco weekly to avoid salt build up.

I think you are too close to the end of flower to be adding more. It shouldn’t matter to much at this stage if you do not add any more as I think you might have plenty of nutrients built up in the soil because I see some slight burning on the tips. Hope this helps.