In the present work, we examine the transformations of aggregated Al13 polycations interacting in suspension with low-molecular-weight organic acids at near neutral pH. The consequences of the interaction strongly depend on the complexing power and concentration of ligands. The most striking feature is the existence of two domains separated by a characteristic adsorbed ligand concentration, corresponding to charge neutralisation by ligands. In the lower concentration domain, ligands interact with the surface aluminum atoms by forming complexes, decreasing the surface charge. In this domain, no soluble aluminum is released from the aggregates. At higher concentration, ligands are adsorbed in excess by ligand exchange and hydrogen bonding, which results in charge reversal. Simultaneously, ligand promoted dissolution of the aggregates occurs, in the form of soluble complexes. It is assumed that dissolution originates from the initially neutral sites. In aquatic media, such radical insitu changes are able to strongly influence the transport and sedimentation of colloids and associated species.