Evaluation of the Water Quality and Farming Growth Benefits of an Intelligence Aquaponics System

Abstract

In 2019, the degree of food self-support in Taiwan was 32.08%, which was lower than that in the previous year by 2.4%. Taiwan does not have the ability to control the availability of food in the face of a food crisis. This study used an aquaponics system to implement the mutualism of fish, flowers, vegetables, and water, as well as to implement the cyclic utilization of water, so that vegetables and fruit could be produced to relieve food shortages in the world. The simulation site of this study was located on a gentle grassy slope alongside Li-tze Lake in Changhua County, Taiwan. In the simulation, three light-tight experimental buckets, with an upper rim diameter of 130 cm, a bottom rim diameter of 125 cm, and a height of 180 cm, were embedded in the ground. The target vegetables and flowers were planted in pots at 17 cm apart, and they were planted on the water surface using the floating island principle. A solar power system enabled a motorized pump to irrigate the plants. An aerator provided adequate aeration to achieve an elementary purifying effect. The experimental results showed that, in terms of the dissolved oxygen, the mean difference of the experimental group was about 1 mg/L, that of the control group was 2 mg/L, and the maximum difference was 6.5 mg/L. As the fish died in April, the ammonia nitrogen value of the control group was 68 times higher than that of the experimental group. Due to the nitrification in July, the ammonia nitrogen decomposed into NO2, which suddenly increased to 13 mg/L and was extremely unsuitable for the existence of aquatic organisms. This amount was five to six times higher than that of the experimental group. In terms of the fish growth rate, the control group could not bear the drastic changes in the water body at the intermediate stage, and all the fish died, whereas the fish in the experimental group were not affected. The results of this study could provide useful data for gardening, aquatic products, and space design staff.