Wholesale CalMag & Iron

Give your plants the critical micronutrients they need with Humboldts Secret CalMag & Iron. Specially formulated with a precise balance of calcium, magnesium, and iron, this powerful additive prevents and corrects common deficiencies that limit growth and yields. Many flowering plants demand higher levels of these nutrients than soil or water alone can provide. That’s where CalMag & Iron comes in—delivering fast-acting support for stronger stems, vibrant leaves, and bigger blooms. Why Growers Love CalMag & Iron: ✅ Corrects Deficiencies – Instantly restores calcium, magnesium & iron levels. ✅ Boosts Flowering & Growth – Supports nutrient absorption and plant health. ✅ Perfect for Coco & RO Water – Highly recommended when growing in coco coir or using reverse osmosis water. ✅ Versatile Application – Use as a root drench or foliar spray in all growing mediums. ✅ Compatible with Base A & B + Golden Tree – Completes your nutrient system for maximum results. How to Use: Apply 2–5 ml per gallon as a soil drench or foliar spray. Safe for use in soil, coco, and hydroponic systems. Check our Feed Chart for detailed guidance. Pro Tip: While Base A+B + Golden Tree provide a complete system, some setups (especially coco and RO water) may still require CalMag support. Strengthen your plants, maximize yields, and prevent deficiencies—add Humboldts Secret CalMag & Iron to your grow today!