Look like 2 if my plants got mag deficiency? Cal m...

If you suspect a nutrient deficiency first thing to do is a good flush and check the ppm and ph of your runoff. If you are using those GH nutrient amounts you listed per gallon your overdosing the hell out of your plants. Use their feeding chart. http://gh.growgh.com/docs/Feedcharts/GH_FloraSeries-DTW_03216am.pdf

I would go real easy with that cal mag. I don't see signs of defeciency. Might be the light though to much blurple. Now flushing you are way to early for that. You look more like week 7 earliest it depends on strain. Now to flush all u have to use is distilled or ro water and water till u get 20% runoff. The way u know it's working is get a ppm meter and measure run off u want something like 0 to 30 ppm good. And by yellowing of your leaves

Growing in soil you really shouldn't be having an issue with calcium or magnesium. I personally can't see any deficiency but its because of your lighting. That purple lighting makes it near impossible to see any specific details in photos. Shut off the light and take pics with flash or under normal household lighting. If you do in fact have a magnesium deficiency then yes calmag will definitely help resolve that. The existing damage from the deficiency won't go away but it shouldn't get worse if theres enough magnesium. You can also just grab some Epsom salts to feed only magnesium if you arent having issues with calcium. Epsom salt should be cheaper than a calmag supplement as well if you don't already have it. https://www.royalqueenseeds.com/blog-epsom-salts-a-natural-hack-to-grow-healthy-cannabis-plants-n837

Hi @Tainopr! I can't see any signs of a Cal/Mag deficiency, but the pictures with the pinkish light don't help 😄 I see signs of overfeeding (burnt tips) that make me think you overfed your baby in the past weeks. If you're suspecting a Calcium and/or Magnesium deficiency, then your last meal made of CaliMagic should solve the issue. Flushing is only recommended if the plant is severely damaged by a toxicity, or during the last days before harvest. I don't think a flush is necessary right now, focus on Phosphorous and Potassium to help the buds to mature, before doing the final flush. Hope this will help, let me know in the comments section if you need any further information, and happy growing! 👊