First grow

Can you update your diary with the amount of nutrients you're using? It doesn't look like a calmag deficiency to me. Cal deficiency will usually be little brown specks and Mag deficiency yellowing between the veins. I'm not really seeing either of those symptoms. Zooming in and seeing the little purplish color, looks like the start of lockout to me. This can be from wrong ph and dosing to strong. Why I'm curious about the nutrient strength you're using.

Mirical grow isn't that good for cannabis, try biobizz light mix or all mix next time.

Possible Causes of Brown Spots and Leaf Curling: Nutrient Deficiency: Magnesium Deficiency: Brown spots between veins on older leaves and leaf curling are classic symptoms of magnesium deficiency. This is likely the primary issue based on the Cal-Mag usage. Nitrogen Deficiency: If the spots are more widespread and the leaves are yellowing, nitrogen deficiency could be a contributing factor. Potassium Deficiency: Brown spots might also indicate potassium deficiency, but it's less likely in this case with the presence of Cal-Mag. Overwatering: Overwatering can lead to root rot, which can cause nutrient deficiencies and leaf curling.   pH Imbalance: If the soil pH is too high or too low, nutrient uptake can be hindered, leading to deficiencies.   Light Stress: If the plant is too close to the light source, it can cause light stress, resulting in leaf curling and brown spots.   Recommendations: Increase Cal-Mag Dosage: Since magnesium deficiency is suspected, increase the Cal-Mag dosage to 10-15ml per gallon and monitor the plant's response. Check Soil Moisture: Avoid overwatering. Ensure the soil is moist but not soggy. Allow the top inch of soil to dry out slightly between waterings. Consider pH Adjustment: If using tap water, check the pH and adjust if necessary to a range of 6.0-6.5 for cannabis. You can use pH up or down solutions to adjust the pH. Light Distance: Ensure the light source is at an appropriate distance from the plant to avoid light stress. Consult the manufacturer's instructions for recommended distances. Nutrient Check: If the issue persists after adjusting Cal-Mag, consider checking for other nutrient deficiencies using a soil test kit. Monitor and Adjust: Continue to monitor the plant's growth and adjust accordingly. If the problem worsens, consider reducing the nutrient dosage temporarily. Additional Tips for First-Time Growers: Start with a Simple Nutrient Schedule: For your first grow, it's best to start with a simple nutrient schedule and gradually increase the dosage as the plant grows. Keep a Journal: Keep a detailed journal of your grow, including watering schedules, nutrient dosages, and any observations about the plant's health. This will help you identify patterns and troubleshoot issues more effectively.