The book "Ecology of Humic Substances in Freshwaters" offers a comprehensive analysis of the role of humic substances in freshwater ecosystems. It highlights the diverse functions of these organic compounds, which not only influence the color of water but also support crucial metabolic processes. The author, Christian Steinberg, goes beyond traditional paradigms and examines the interactions between humic substances and aquatic organisms. Both geochemical and physiological as well as ecotoxicological aspects are taken into account. The work stands out from other publications by detailing the complex relationships between the structure and effects of humic substances, without reproducing the common breaks between chapters found in anthologies. This thorough examination makes the book a valuable resource for professionals and students in environmental sciences, ecology, and chemistry.