Potassium Sulfate — Water Soluble Sulfur Source

Potassium Sulfate — Water-Soluble Potassium & Sulfur for Hydroponics & Fertigation

Potassium sulfate (SOP) is the premier dual-nutrient potassium and sulfur source for professional hydroponic and fertigation programs. Unlike potassium chloride (MOP), SOP delivers potassium without chloride — making it the preferred potassium source for chloride-sensitive crops and recirculating systems where chloride accumulation is a concern.

As a sulfur source, SOP provides 17–18% sulfate sulfur — immediately plant-available and essential for protein synthesis, enzyme activation, and chlorophyll production. Custom Hydro stocks multiple SOP grades and analyses to match your crop requirements and system type.

SOP as a Sulfur Source

• 17–18% sulfate sulfur — immediately plant-available; no conversion required
• Co-delivered with potassium — single product supplies both K and S
• Chloride-free — no chloride interference with sulfur uptake or soil chemistry
• Compatible with all systems — drip, NFT, DWC, center pivot, and foliar

Available SOP Grades

• Organic SOP Standard Fines 0-0-50 + 17% S — OMRI certified; fine-screened for rapid dissolution
• SOP 3IX 0-0-53 + 18% S — highest-purity crystalline SOP via ion exchange; ultra-low chloride
• Haifa SOP BIO 0-0-52 + 18% S — organic-certified; EU compliant
• Haifa SOP GG 0-0-51 + 18% S — greenhouse-grade; fast dissolving; acidic pH