In aquaculture, fish are constantly encountering ammonia stress that negatively impacts growth and health. Ammonia is a toxic biproduct formed during protein degradation that is excreted as waste. When ammonia levels in the water get too high, it can cause several problems such as damaging the gills. Gill damage makes it hard for fish to breathe. High ammonia levels can also cause burns and sores on the skin and fins. In the wild high ammonia is not normally a problem due to bacteria found within the sediment that detoxifies ammonia. In captivity these bacteria must be introduced to negate ammonia stress. In this experiment, we wanted to investigate if high levels of ammonia cause physiological and immunological changes in tilapia. Tilapia were reared in high ammonia for four weeks and sampled to check for physiological and immunological status. To determine if delayed sampling time after capture is a factor that affects the quality of data, fish were caught and then held in a bucket for ten minutes before sampling instead of sampling within two minutes of capture. There was a total of four treatments: control, delayed, ammonia, and ammonia delayed. Length, weight, Fulton’s condition factor, packed cell volume, blood glucose, serum lysozyme, and plasma protein were measured at the end of four weeks. Average packed cell volume was significantly different between control delayed and ammonia delayed treatments (p = 0.035). There was a significant difference in average blood glucose between control and ammonia delayed treatments (p = 0.031). Average weight was significantly different between control and ammonia and between control and ammonia delayed treatments (p = 0.235; p = 0.001). There was no significant difference between any of the treatments for the remaining parameters. The data shows that four weeks of high ammonia does not contribute to significant health problems, other than weight, within the fish. It also appears that delaying sampling by five minutes is an insignificant factor to data quality. If the fish were held in a high ammonia environment for a longer period of time the health of the animal may start to dwindle.