Floating phytoremediation offers a feasible, ecofriendly, and economically viable method for treating wastewater. The objective of this study is to assess the effectiveness of Eichhornia crassipes and Pistia stratiotes in treating domestic wastewater by varying loading strength and hydraulic retention time (HRT). The growth parameters of the plants were assessed and linked to the removal of contaminants. The wastewater phytoremediation by E. crassipes and P. stratiotes conducted for twenty-two days in a green house. Result showed that Eichhornia crassipes able to treat 50% strength of wastewater (50WH) efficiently with removal of ammonia, phosphate, and COD by 97.4%, 68.5%, and 54.0%, respectively, at the HRT of three days. The 50WH experimental units showed the lowest relative growth rate (RGR). The results proved the higher efficiency of E. crassipes in treating the domestic wastewater.