For optimal fish health, DO concentration should be at _____ or more.

The optimal dissolved oxygen (DO) concentration for fish health is critically important in aquaculture. A concentration of 5 mg/L or more is typically considered sufficient to support healthy growth and metabolic functions in most species of fish. This level of oxygen allows for adequate respiration, encourages efficient feeding, and supports the overall health of the fish, reducing stress and the likelihood of disease.

Maintaining this oxygen level is essential, particularly in intensive aquaculture systems where fish are kept in higher densities, as it helps to ensure that fish can thrive in a controlled environment. Lower concentrations may lead to hypoxia, which can impair fish health and growth, increase mortality rates, and create unfavorable conditions in the aquatic environment. Thus, understanding the importance of maintaining DO levels at or above this threshold is crucial for successful fish farming practices.