Improving Tilapia Growth with Vetiver Grass in an Aquaponic System

Tilapia aquaculture is growing vertiginously in the world, reaching 7.02 million tons in 2020. In Mexico, the same year it reached 72.6 thousand tons. These production values have increased environmental impact and production costs. In Mexico, there is a pre-Hispanic aquaponics system, where people culture corn, bean fishes and other organisms. Taking this system as a basis, the aim of this work was to demonstrate the benefits of Vetiver grass in tilapia aquaculture. Tilapia juveniles in three mini-ponds were cultured for ten weeks, using an aquaponics system with Vetiver and one mini-pond without Vetiver. Water parameters like ammonia, nitrates, dissolved O2, pH etc., and also, the increase of tilapia weight were recorded during the experiment. Results indicated that ammonia decreased, nitrate increased and tilapia weight increased more in mini-ponds with Vetiver than without Vetiver. A von Bertalanffy simplified model was used to calculate the time required for tilapia to reach the commercial size (around 500 g). The time obtained with and without Vetiver was 48.6 and 54.4 weeks respectively. Moreover, in farm tilapia aquaculture, this will decrease production cost, due to less amount of feed supplied for the tilapia growth; also, a reduction of environmental impact to coastal ecosystems will be obtained, since the amount of ammonia produced in mini-ponds with Vetiver was 4.56 times less than mini-pond without Vitier at end of ten weeks. Moreover, tilapia culture with Vetiver, generates an aggregated value, because Vetiver is used in perfumes production, which reached 45.2 billion US dollars in 2020.