Abstract marine aquaculture, using natural sea water, causing increased excretion of nitrogen compounds from marine animal waste. Cause spoilage subsequent aim of this study was to solve the problem by means of biological studies, the ability to absorb nitrogen, algae cluster. (CaulerpalentilliferaJ. Agardh) using sea water and waste water from fish ponds of Sriracha Fisheries Research Station conducted during April 2558 by 10-5 were divided into two phases with the first study. ability to absorb nitrogen, algae bunch of grapes in the sea when the two efficacy studies in nitrogen adsorption of algae bunch of grapes in the waste water from the fish cartoon Research station fisheries Sriracha by a process tank 4 liter. water 3 liters of 3 sets to 1 suppresses algae (control) set the second seaweed cluster of three grams, as well as the analysis of ammonium and nitrate before and after the trial of three days in the lab. the first performance in nitrogen adsorption of each series of experiments, the following results in the absorption of nitrogen of each series of experiments, the following results: 13.9433 ± 0.0617, 16.8270 ± 0.0029 and 15.7911 ± 0.0183 μg-at N / l / at N /. l / g algae live / day results showed that algae grapes can treat nitrogen in the water with mineral content and highly effective therapy in a short period of this research will lead. Research development efficacy in the treatment of water quality in freshwater algae to produce a water filtration system in the aquarium next cartoon