Studies on growth of groupers in indoor tanks with recirculating sea water systems are very few. The present study on the grow-out production of the Malabar grouper, Epinephelus malabaricus, was carried out in indoor FRP tanks of 5 ton capacity, with recirculating sea water systems, using indigenously made in situ biofilters. Pre-sanitized, wild caught fingerlings were stocked at the rate of 12 to 17 numbers, with the total biomass not exceeding 1200-1400g, in each tank. Fingerlings were fed with trash fish twice a day initially, at 10% of their body weight. No supplementary formulated feed was given throughout this study period. After overcoming the initial period of stress due to transportation, growth was observed to be quite fast. At the end of seven months the fishes attained a weight ranging between 750 and 800g. The growth obtained in the present system was comparable to those obtained in other systems.