Cal mag help

It's look like a boron or calcium deficit. How high the humidity is?

That looks to me like you have an excess of nutrients or lock out. When your feeding make sure you give a break every 3 feeds with just water, this will help move all all the nutrient salts around the soil. Also make sure there's airflow and moisture around or the leaves will also dry up like that. 🌱👍

Yes, slight deficiency of calcium or acid pH. First check the pH of the outlet water, if it is ok from 2ml / l of cal mag, then 1 ml / l 1 time a week.

The recommended dosage for Cal-Mag Plus is 3 to 5 mL per gallon of water. 5mL equals one teaspoon. So if you were using a 5 gallon bucket to fill up, you would use between 15 and 25 mL of Cal-Mag supplement. This would be the correct dosage of Cal Mag to use in soil if you have an existing magnesium or calcium nutrient deficiency in your plants. While the directions of 3-5 mL are recommended Cal mag dosage on the label, if you’re using it as a preventative measure (rather than correcting an existing problem) then you can go with a weaker ratio such as 1 mL per gallon in soil and coco grows. If using a soiless medium such as coco coir, it’s a good idea to load up on the Cal-Mag prior to transplanting your established clone or seed. Start with 5 mL/gallon for the first few waterings, then scale back to 1-1.5 mL/gallon thereafter. Watch your vegetating plants’ leaves closely to check for early signs of a calcium or magnesium deficiency. Really get in there and inspect them, it’s the best way to catch any nutrient or pest issues. The quicker you catch them, the easier it is to recover. Hope this helps!!