["European Journal of Education, Volume 61, Issue 2, June 2026. ", "\nABSTRACT\nScience education, from an early age, plays a key role in promoting sustainability. Within this framework, water emerges as a valuable resource for studying fundamental scientific principles and fostering critical reflection on its sustainable use. This quasi‐experimental study involved 168 primary students (ages 9–11) from public schools in Extremadura, Spain, who participated in a hands‐on activity building a sand filter. To assess the impact of the intervention, a customised questionnaire on scientific knowledge, attitudes and emotions towards science and water sustainability was completed before and after the activity. Findings indicate that the intervention improved scientific knowledge, promoted sustainable attitudes and behaviours towards water, increased interest in science and strengthened emotional connections with both scientific topics and water‐related issues. This study underscores the need for student‐centred approaches that promote meaningful learning and support the Sustainable Development Goals from early educational stages, serving as an enriching complement to existing science programmes in schools.\n"]