The Effectiveness of Using Biofilter With the Addition of Palm Fibers on the Growth of Red Lettuce (Lactuca sativa var. Crispa) and Tilapia (Oreochromis niloticus) in Deep Flow Technique (DFT) Aquaponics Systems

The aquaponics system is a closed circulation system that uses interactions between plant and fish cultivation. Problems that often occur in the development of aquaponic systems, include the increase in the accumulation of toxins resulting from fish metabolites such as ammonia. The use of biofilters in the aquaponics system is expected to increase the transformation of ammonia into nitrates which can be used directly by plants. The addition of palm fiber to the bio-ball biofilter is expected to filter large particles in water. This research was conducted to determine the effect of adding palm fiber to the bio-ball biofilter on the growth of red lettuce (Lactuca sativa var. Crispa) and tilapia (Oreochromis chromis) growth. In addition, we also want to know whether there is an effect on plant growth based on different positions in the Deep Flow Technique (DFT) system model. This research was conducted in a Randomized Block Design (RBD) with 2 installations that had different biofilters and 5 plant positions in each installation. The first installation uses a bio-ball biofilter as a control and the second installation uses a bio-ball biofilter with the addition of palm fiber (1:1). In each installation, the effect of each plant position which has a different distance from the inlet was observed with the order of position 1 (30 cm); position 2 (60 cm); position 3 (90 cm); position 4 (120 cm); and position 5 (150 cm) on the growth of red lettuce (L. sativa). Each position treatment was repeated 12 times. Measurements were made on growth parameters and plant biomass, fish growth, water quality (pH, TDS, and EC), and environmental conditions (temperature, humidity, and light intensity). The data obtained were processed using a two-way ANOVA test and the BNJ Tukey test with a 95% confidence interval. The highest plant growth and plant biomass were obtained in the control biofilter treatment with positions 1 and 2. The highest fish growth was obtained in the palm fiber and bio-ball biofilter treatment. This is possibly caused by a decrease in nutrient levels due to the addition of palm fiber to the bioball biofilter. The addition of palm fiber can filter fish waste and large food scraps which also contain nutrients for plant growth so nutrients for red lettuce plant growth (L. sativa) are not optimal. Conversely, the addition of palm fiber to the bioball biofilter can improve water quality to support tilapia growth (O. niloticus).