Overall, the fish scale teabags were easy for students to use. The use of transparent teabags allowed students to visually monitor the color changes on the scale surfaces during the adsorption process 245 (Figure ). After a 30-minute contact time with the copper(II) sulfate solution, the initially white scales quickly turned light blue, indicating the adsorption of Cu²⁺ ions on their surfaces. Despite the relatively low concentrations used in this experiment, students should exercise caution when handling aqueous solutions containing any heavy metal. They should also be made aware of the environmental hazards associated with improper waste disposal and encouraged to manage their chemical waste responsibly.