A novel type of diagrams based on graphical and numerical methods, which quantitatively describe the distribution of soluble and insoluble, inorganic and organic, monomeric and polymeric aluminium species in heterogeneous multicomponent systems "basaluminite - soil solution" has been used. This approach utilizes the thermodynamic relationships together with original mass balance restraints, where the mineral phases are clearly expressed. The factors influencing the distribution of soluble and insoluble aluminium species in aquatic systems in a large range of pH values have been investigated. It has been found that the SO₄ ^2- concentration has a remarkable influence on the distribution of aluminium heterogeneous speciation. The developed new type of diagrams can be used to interpret data obtained within the framework of water quality monitoring programs.