This study examined the water quality of textile wastewater and the efficiency of decolouring agent Dicyandiamide-formaldehyde resin added with Poly dimethyldiallylammonium chloride (Polyadmac) and Chitosan Powder. The optimisation study investigated the influence of factors such as dosage volume, pH, mixing speed, and retention time. Raw water samples were collected to observe the water chemical oxygen demand (COD), total suspended solids (TSS), and colour using a jar test to compare with Malaysian standard effluent. The mixing speed and time were constant: mixing speed at 200rpm in 15 min, slow mixing at 45rpm in 30 min, and retention time in 30 min. The dosage range for DCD-F is 60mg/L - 100mg/L, Polydadmac in 1mg/L - 5mg/L, and chitosan in 100mg/L - 500mg/L. Both solutions impacted the removal of COD, TSS, and Colour and maintained the pH. Polydadmac removed 92.74% of COD, 99.26% of TSS, and 95.04% of Colour, and the final pH was still 7 to 8. Moreover, Chitosan removed 88.83& of COD, 89.01% of TSS, and 93.47% of Colour. However, the combination of 100mg/L DCD-F and 300mg/L of Chitosan fails to sustain a pH above 5.5. Polydadmac demonstrates superior performance as a coagulant aid compared to Chitosan. This is due to its ability to effectively remove contaminants and maintain the desired pH levels, which align with the established effluent standards. However, Chitosan can still be used as a coagulant to remove COD, TSS, and Colour. Coagulant aid performance and cost-effectiveness significantly provided valuable insights for cost-benefit analysis in the textile industry and added to the broader discussion on optimising coagulant aids in wastewater treatment processes.