Monoammonium Phosphate (MAP) 12-61-0 is a technical-grade, 100% water-soluble fertilizer and one of the most concentrated water-soluble phosphorus sources available. Each pound delivers 61% available phosphate (P₂O₅) and 12% ammoniacal nitrogen, dissolving completely with no residue.
Phosphorus supports root development, flowering, and fruit set, and the ammonium-form nitrogen helps acidify the root zone to keep phosphate plant-available. Because it dissolves clear without clogging emitters, MAP 12-61-0 is engineered for drip irrigation, fertigation, hydroponic reservoirs, banded liquid starter applications, and foliar correction. Its mildly acidic solution makes it especially useful on alkaline and hard-water soils where phosphorus would otherwise lock up.
This is the water-soluble grade; for dry broadcast on fields, lawns, and garden beds, the granular MAP 11-52-0 grade is the appropriate choice. In hydroponic and fertigation systems, keep MAP separate from concentrated calcium- and magnesium-bearing fertilizers, since combining them in concentrated stock causes precipitation — run separate stock tanks. Check solution pH after adding, and for foliar use, spray in early morning or late afternoon.
CDFA registered and third-party lab tested for heavy metals, with results consistently well below required limits.