The phytoextraction potential of water hyacinth (Eichhornia crassipes) in the treatment of a representative sample of water of Madín Dam, contaminated with 24.45 mg/L of aluminum (Al) and 5.10 mg/L iron (Fe) was evaluated. Two 60 days experiments were performed, one using young and adult plants and the other with young ones, extracted and substituted every 15 days. The percentage of maximum removal observed in the hyacinth exposed for 60 continuous days was the one of young hyacinths, namely 72%. Besides, those hyacinths extracted every 15 days extracted about 86% of the metals in contaminated water. Eichhornia crassipes turned to be a Al and Fe tolerant species, but not capable of transporting those metals from the roots to the leaves. However, its harvest implies the removal of the whole specimen and therefore the complete extraction of the plant. This indicates that a post-treatment of the extracted hyacinth as a hazardous material would be required, due to its high content of heavy metals.