Cal-Mag 15-5-15 for Soft Water

Jack’s Nutrients Cal-Mag 15-5-15 is a true one-part hydroponic fertilizer designed to simplify feeding while maintaining peak plant performance. With 4% calcium and 2% magnesium, it’s ideal for water sources low in Ca and Mg, preventing common deficiencies before they start. The 80% nitrate nitrogen provides a steady, clean source of N that supports vigorous growth without excess ammonium. A complete suite of micronutrients is included for balanced nutrition in recirculating, drain-to-waste, and other hydroponic systems.

Complete Hydroponic Nutrient with Micronutrients

Growers get consistent EC targets, fewer compatibility issues, and simpler stock-tank management thanks to its single-tank, water-soluble composition. Use during vegetative growth or whenever your program calls for a balanced NPK (15-5-15) with added Ca and Mg to stabilize water quality and media chemistry. The result is uniform growth, stronger stems, and improved color—batch after batch—across commercial and hobby hydroponic setups.

Benefits:

• One-tank, water-soluble formula simplifies mixing and dosing.

• 4% Ca + 2% Mg balances soft water and prevents deficiency symptoms.

• 80% nitrate nitrogen supports steady, clean vegetative growth.

• Full micronutrient profile promotes uniform color and strong structure.

• Consistent EC and compatibility for recirculating and drain-to-waste systems.