Potassium Magnesium Sulfate — Water Soluble Potassium Source

Potassium Magnesium Sulfate (KMS) — Natural Chloride-Free Potassium Source

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

OMRI certified for organic production. Available in ultra-fine (UltraFines) and standard mini-granule grades.

KMS as a Potassium Source

• 22% potassium (K) — immediately plant-available; chloride-free
• Co-delivered with Mg 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. Potassium Sulfate (SOP)

• KMS supplies K + Mg + S simultaneously; SOP supplies only K + S
• KMS is preferred when magnesium is also needed; SOP when only K and S correction is required
• KMS has lower K₂O (26%) vs. SOP (50–53%) — use KMS when Mg demand is high

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)