ABSTRACT. Three duckweed geographic isolates were grown on varying concentrations of swine lagoon effluent in agreenhouse to determine their ability to remove nutrients from the effluent. Duckweed biomass was harvested every otherday over a 12-day period. Duckweed biomass production, nutrient loss from the swine lagoon effluent, and nutrientcontent of duckweed biomass were used to identify effluent concentrations/geographic isolate combinations that areeffective in terms of nutrient utilization from swine lagoon effluent and production of healthy duckweed biomass. WhenLemna minor geographic isolate 8627 was grown on 50% swine lagoon effluent, respective losses of TKN, NH 3 -N, TP,OPO 4 -P, TOC, K, Cu, and Zn were 83, 100, 49, 31, 68, 21, 28, and 67%.