Potassium Magnesium Sulfate — Water Soluble Magnesium Source

Potassium Magnesium Sulfate (KMS) — Natural Water-Soluble Magnesium Source

Potassium magnesium sulfate (KMS), also known as langbeinite, is a naturally mined mineral delivering 11% magnesium (Mg), 22% potassium (K), and 22% sulfur (S) in a single, chloride-free product. As a magnesium source, KMS provides immediately plant-available magnesium co-delivered with potassium and sulfur — making it a highly efficient alternative to magnesium sulfate (Epsom salt) when potassium and sulfur are also needed in the program.

Unlike magnesium sulfate (MgSO₄), KMS supplies magnesium alongside potassium and sulfur simultaneously, reducing the number of separate inputs required in hydroponic and fertigation programs. OMRI certified for organic production.

KMS as a Magnesium Source

• 11% magnesium (Mg) — immediately plant-available; essential for chlorophyll production and enzyme activation
• Co-delivered with K and S — three nutrients in one product; reduces input complexity
• Chloride-free — safe for chloride-sensitive crops and recirculating systems
• OMRI certified organic — approved for certified organic production
• Naturally mined — langbeinite mineral; no synthetic processing

KMS vs. Magnesium Sulfate (Epsom Salt)

• KMS supplies K + Mg + S simultaneously; Epsom salt supplies only Mg + S
• KMS is preferred when potassium is also needed; Epsom salt when only Mg correction is required
• KMS UltraFines dissolve rapidly — comparable dissolution speed to Epsom salt in warm water

Available Products

• Diamond K KMS UltraFines — ultra-fine particle size for rapid dissolution; ideal for hydroponics and fertigation (1 lb, 4 lb, 17.5 lb, 50 lb)
• Sul-Po-Mag K-Mag Standard Mini-Granule — uniform mini-granule for blending and broadcast application (50 lb)