Growth performance of red tilapia was demonstrated from fingerling to market stages in an ASA LVHD coastal cage trial using an all-plant protein, soy-based growout feed. Red tilapia in three replicate cages of size 6.4-m3 were fed to satiation twice daily with the ASA 32/6 soybean meal-based feed in extruded, floating pellet form. Average monthly salinity in the Longmen area was 7.5 ppt, within a range of 0 ppt to 19 ppt. Tilapia grew from 64 g to 493 in 124 days, with an average FCR of 1.41:1. Fish survival averaged 91.7%. Fish production averaged 724 kg per cage (113 kg/m3). Net economic return averaged RMB 1,080 per m3, at an average market price of RMB 16/kg for red tilapia cultured in brackish water. Return to investment averaged 48.3% for the three trial cages. The trial demonstrated the feasibility of culturing red tilapia in cages in a coastal area with fluctuating salinity and overall brackishwater conditions.