Adopting a greywater treatment system that provides economical, effective, and sustainable treated greywater over a longer span helps to address water scarcity. The present study focuses on treating greywater generated from hostels using a floating plant treatment system (FPTS) planted with water hyacinth. The additional units, a sand filter and an activated charcoal filter, were attached in series to FPTS to improve the treated greywater quality. The treatment system was operated for 90 days with daily monitoring of influent and effluent parameters. The treatment performance was evaluated based on the removal efficiency for total suspended solids (TSS), turbidity, chemical oxygen demand (COD), ammonia, sulphate, phosphate, and faecal coliform (FC) of 74.81% ± 5.74%, 99.76% ± 0.05%, 95.70% ± 4.10%, 99.16% ± 2.08%, 48.22% ± 1.80%, and 100%, 97.27% ± 1.48%, respectively. The study showed that the system effectively treats greywater, making it suitable for non‐potable purposes on educational institution's campuses.