Experimental setup for floating treatment wetland experiments evaluating the influence of alkalinity (0, 100, 200, 300 and 400 mg^.L⁻¹ CaCO₃) and plant species (‘Rising Sun' Japanese iris, switchgrass, and upright sedge) remediation of nutrients from simulated nursery runoff. Fifty experimental units were randomly assigned a treatment combination or as an alkalinity control with no plants present. The five holding tanks permitted ease of mixing and consistent alkalinity exposures for treatments each time the experimental units were refilled.