Poly[diaquatris(μ(6)-4,6-dioxo-1,4,5,6-tetra­hydro-1,3,5-triazine-2-carboxylato)tripotassium]

The asymmetric unit of the title compound, [K(3)(C(4)H(2)N(3)O(4))(3)(H(2)O)(2)](n), contains two potassium cations (one in general position, one located on a twofold rotation axis), one and a half oxonate anions (the other half generated by twofold symmetry) and one water mol­ecule. As a result of the twofold symmetry, one H atom of the symmetric anion is statistically occupied. Both potassium cations are surrounded by eight oxygen atoms in the form of distorted polyhedra. Adjacent cations are inter­connected by oxygen bridges, generating layers parallel to (100). The aromatic ring system of the oxonate anions link these layers into a network structure. The crystal packing is stabilized by N—H⋯O, O—H⋯O and O—H⋯N hydrogen bonds, three of which are bifurcated. In addition, inter­molecular π–π stacking inter­actions exist between neighboring aromatic rings with a centroid–centroid distance of 3.241 (2) Å.