POTENTIAL OF NUTRIENT DEFICIENCY UNDER THE DEVELOPMENT OF FILAMENTOUS ALGAE IN AQUAPONICS

Abstract

The article addresses the issue of filamentous algae development in aquaponic systems, their impact on the chemical composition of water, and possible control measures. Aquaponics, combining aquaculture and hydroponics, is a promising technology for restoring agricultural production in Ukraine under conditions of limited land resources. The main goal of the study is to establish the conditions for the development of filamentous algae, particularly Spirogyra, and assess their negative impact on the cultivation of leafy lettuce and African catfish. The research methodology included monitoring the chemical elements of water composition, analyzing laboratory data, and performing a systematic analysis of factors that contribute to the appearance of algae. It was established that the main causes of excessive filamentous algae proliferation are the imbalance of macroelements (nitrogen, phosphorus, potassium), elevated ammonia levels in water, as well as uncontrolled lighting and temperature. During the dark phase of photosynthesis, filamentous algae consume oxygen, which may lead to hypoxia in fish. Furthermore, biofouling of aquaponic system components by algae reduces filter efficiency, restricts water flow, and creates additional technical difficulties. The research results showed that high concentrations of nitrates and phosphates promote the growth of filamentous algae, which actively assimilate these elements, creating a deficiency for plants. Specifically, under conditions of intensive algae development in the system, the extraction of up to 50% of nitrate nitrogen and 70% of phosphorus may be observed, negatively affecting the yield of lettuce and other crops. A set of measures to combat filamentous algae has been proposed, including lighting control, regulation of water circulation speed, maintaining an optimal balance of nutrients, and monitoring water temperature and pH. The obtained results will help improve the efficiency of aquaponic systems and ensure sustainable production in a controlled environment.