DESIGN AND CONSTRUCTION OF HYDROPONICS SYSTEM FOR ARTIFICIAL PHOTOSYNTHETIC WATERMELONS.

Abstract

The purposes of this research were to study the automatic solutions control system used in hydroponics. And choose Watermelons to experiment. Watermelons produced by greenhouse systems performed well and they were well–liked by consumers. According to the market, using less chemical insecticide was experimented including 3 steps; 1) nutrient solutions and nitric acid were prepared, 2) the automatic solutions control system was designed, 3) lighting control system was launched during 15–60 days of planting. Electrical Conductivity (EC) and potential of Hydrogen ion (pH) were measured and sent to microcontroller in order to compare with the measurement that set during 3 stages of planting. The first stage was 1–7 days of planting and EC was set to be 0.50–1.00mS/cm. The second stage was 8–14 days of planting and EC was set to be 1.10–1.60mS/cm. The third stage was 15–60 days of planting and EC was set to be 1.70–2.40mS/cm. For pH, it was set to be in appropriate level which was 5.5–6.5 for the whole period. Moreover, the lighting was increased to be 90 lux from 10 pm to 1 am. It was found that the automatic solutions control system which was used to measure EC and pH was working efficiently as designed and expected during 15–60 days of planting. The result of the experiment showed that the lighting control system which controlled the light for watermelons was well operated as planned.