These articles below will help you identify the symptoms and inform you on how to fix the nutrient lockout or deficiencies in your plants.
Plant Stress: Why Your Grow Lights, Nutrients, and Buckets Might be Harming Your Plants
The Best Way to Fix Nutrient Lockout and How to Prevent It
Heavy Metal Deficiencies: Identifying & Treating Boron, Iron, Magnesium, and Manganese Issues
Grower Q&A: Why Are My Leaves Turning Yellow?
Identifying and Treating Nitrogen Deficiencies In Your Plant