The commercial catfish industry has been increasing fish stocking density coupled with increased aeration and feeding rates. Long regarded as photoautotrophic systems, intensive earthen production systems may achieve feeding rates that surpass the nitrogen assimilatory capacity of the phytoplankton population. Hybrid catfish (7,500, Ictalurus punctatus x I. furcatus) were stocked in 0.25-acre (0.10-ha) earthen ponds equipped with three 2-hp (1.5 kW) paddlewheel aerators. Dissolved oxygen concentration of each pond was measured by a monitoring system and energized aerators to maintain the minimum dissolved oxygen at either 3.5 mg O2/L (HighDO) or 1.5 mg O2/L (LowDO). Water quality was measured weekly and feeding rates reached 660 ± 48 and 439 lbs/acre/day for the HighDO and LowDO treatments, respectively. Fish grew significantly smaller in LowDO ponds (0.74 ± 0.02 lbs) than HighDO ponds (1.00 ± 0.03 lbs) but did not have different survival (95% average). Production reached 29,400 ± 1200 lbs/acre in HighDO ponds but only 20,700 ± 800 lbs/acre in the LowDO ponds. Total ammonia concentration was not different between treatments but was higher in August and September in LowDO ponds. Total oxidized nitrogen (TON, NO2--N + NO3--N) was significantly higher from August through October in HighDO ponds, largely driven by the concentration of nitrate. The increased aeration and oxygen present in ponds managed with higher dissolved oxygen concentration allowed excess ammonia to be oxidized to nitrite and ultimately nitrate, leaving the water suitable for catfish production.