Indoor Hydroponics: A Potential Solution to Reuse Domestic Rinse Water

Abstract

The objective of this study was to evaluate the potential of reusing domestic rinse water in an indoor hydroponic system and compare the growth pattern of Coleus plants using tap water and rinse water. A preliminary survey evaluatedthe knowledge about, home gardening, hydroponics, water usage and utility of rinse water in urban households. The experimental setup consisted of water culture hydroponic system with peat moss media. Data were collected and analyzed from 4 sample groups: Group A (tap water), B (tap water with NPK fertilizer), C (rinse water) and D (rinse water with NPK fertilizer) in a randomized experimental design (N=20) with five replicates.The study was conducted indoors in an urban household under controlled temperature (78ºF), light and humidity (60-70%). Parameters analyzed for assessment of plants growth included height (in millimeters), number of new leaves and leaf surface area. Environmental parameters including, pH and TDS (Total Dissolved Solids in parts per million) of the hydroponic solution, and pH and moisture of soil were also recorded. Descriptive statistical analysis and independent comparisons were done with a 95% assumed significance level (p<0.05).During the 20th, 25th and 30th day, plant height in Group A was significantly (p<0.05) higher than that of Group B and plant height in Group C was significantly higher than in Groups B and D.In terms of the environmental parameters, while rinse water had an alkaline pH, the addition of NPK fertilizer (Groups B and D) resulted in significantly lower pH.Based on the present study results, domestic rinse water can be reused as a successful alternative for tap water in indoor hydroponic cultivation of plants without the need for any additional fertilizer.