The objective of this study was to determine the effect of superdosing 2 sources and levels of phytases on nursery pig performance in a commercial setting. Phase 1 (crumble/meal mix), phase 2 (common meal) and phase 3 diets were corn-SBM with 4, 10, and 20% DDGS respectively and contained 0.47, 0.40, and 0.35% av. P respectively. They were budgeted at 5.7 and 6.4 kg/pig for phase 1 and 2 and until they moved out of the nursery for phase 3. Six experimental diets were fed: Positive Control (PC), Negative Control (NC, PC minus 0.12% av. P), 500 and 1000 FTU/kg of Optiphos 2000 (Huvepharma USA, Inc.); and 500 and 1000 Quantum Blue 5G (AB Vista) were added to the NC. We had 10 pens per treatment and 21 pigs/pen. Pigs (Geneticpork Fertilis 25 female x PIC Line 359 Sire) were sourced out of a sow farm negative to PPRS, PED virus and M.hyopneumonea. Pens were weighed at 7 d interval. Pens were the experimental units and we found no gender by treatment interactions therefore gender was removed from the model. The ANOVA was performed using SAS statistical software (SAS Institute, Cary, NC). From d 0 to 44 (Overall), all phytase treatments had higher (P < 0.01) final pig BW, increased (P < 0.01) ADG, and higher (P < 0.01) ADFI when compared with either PC or NC. Positive Control and NC treatments were not different for those traits. All phytase treatments had decreased (P = 0.03) FCR when compared with the PC but were not different than the NC. There were not significant differences in any performance traits between Optiphos and Quantum Blue. Increasing the levels of phytases from 500 FTU/kg of complete feed to 1000 FTU/kg of complete feed with either source did not result in improved performance. In this trial, 500 FTU/kg of complete feed performed as well as 1000 FTU/kg of complete feed of either Optiphos or Quantum Blue for commercially raised nursery pigs.