Nitrate (NO3-N) is the stable end-product of the aerobic nitrification process. As water reuse is extended, nitrate levels can easily rise into the hundreds of mg-N/L impacting the growth and health of many cultured species. Bacteria can remove the nitrate, ultimately converting nitrate to the inert nitrogen gas (N2) through the denitrification process. This is a natural process that occurs whenever oxygen is depleted in a carbon enriched environment. The process is easily implemented either as a fixed film or suspended growth process using aquacultural sludge, liquids (such as methanol, or ethanol) or solids (starch, bioplastics, sugar) as a carbon source. It is not a difficult process to implement.