Hasil penelitian ini menunjukan dari konfigurasi pararel, seri dan Tunggal, konfigurasi peltier yang lebih optimal untuk sistem hidroponik adalah konfigurasi tunggal menggunakan 2 peltier dengan total arus, tegangan dan daya yang digunakan berturut-turut yaitu 12.023A, 11.99V dan 144.209 W. Dimana konfigurasi tersebut mampu menurunkan dan menjaga suhu pada 25 – 25.5°C untuk air 10L pada sore hingga pagi hari dengan waktu untuk menurunkan air dari 25.5 °C sekitar 10 menit. ......The increase in population not only has positive impacts but also raises the need for food. Hydroponics, as a type of horticulture, has great potential to address this issue. The development of hydroponics can also be promoted through automation, which makes the control of parameters more accurate. Besides the main parameters commonly controlled in hydroponics, such as nutrients and pH, water temperature is also a parameter that needs attention. Water temperature affects plant growth, particularly related to plant roots, in terms of nutrient absorption and dissolved oxygen. This study will further discuss the low energy water temperature cooling system in hydroponics using a peltier module TEC1-12706.
The results of this study indicate that from the parallel, series and single configurations, the more optimal peltier configuration for the hydroponic system is a single configuration using 2 peltiers with a total current, voltage and power used respectively, namely 12.023A, 11.99V and 144.209 W. Where this configuration is able to lower and maintain the temperature at 25 - 25.5 ° C for 10L of water in the afternoon to morning with a time to lower the water from 25.5 ° C of around 10 minutes.
Azolla sp. has been widely used as a complement to inorganic fertilizers in vegetable cultivation to increase nitrogen availability. The aim of the study was to determine the effect of adding Azolla sp. fresh water spinach on vegetative growth and the effect of Azolla sp. in reducing the use of inorganic fertilizers. The vegetative growth parameters analyzed included wet weight, dry weight, root length, and chlorophyll content. The research was carried out from February to July 2022 at Gunung Putri, Bogor and the Merck Collaboration Lab FMIPA UI, Depok. Planting using the hydroponic cultivation technique of the wick system for 21 days with three types of nutrient solutions with 5 treatments, namely: nutrien solutions AB Mix 100% + 0 g Azolla sp. (P1), AB Mix 50% + 0 g Azolla sp. (P2), AB Mix 50% + 20 g Azolla sp. (P3), AB Mix 50% + 40 g Azolla sp. (P4), and Water + 40 g of Azolla sp. (P5). The results showed that the treatment with AB Mix 50% + Azolla sp. 20 and 40 g (P3 & P4) showed results that were able to compensate for the control treatment (P1 & P2). Dunn's statistical test also showed no significant difference in the vegetative growth of the control (P1 & P2) with the treatment given the addition of Azolla sp. (P3 & P4). Meanwhile, the addition of Azolla sp. 40 g of nutrient solution in the form of water as the sole bio-fertilizer resulted in low water spinach growth. Azolla sp. can be used as a substitute for adding nutrients to inorganic fertilizers (AB Mix), but cannot replace the use of inorganic fertilizers.