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Development of a Hydroponic system

University of the Sacred Heart

STEMmED II Research Component

Project sponsored by Title V funds, HIS-STEM Education Department United States

Del Toro Carmen, Zenaida Adrovet, Desiree Rexach


 Hydroponics is a technique of growing plants with water and nutrients without soil. The National Aeronautics and Space Administration (NASA), Cornell University, and researchers all over the world are seriously investigating this technique due to overpopulation problems, significant amount of soil lost each year, and the amount of food being produced. The objective of this study is to develop a simple hydroponic system that anyone can use as a possible solution to address this problem. This research is divided in two phases. In the first phase the total dissolved solids (TDS) and the acidity/alkalinity measurement (pH) of the nutrient solutions, were tested and some seeds were sown. The total dissolved solids (TDS) determine the nutrient concentration. Each plant has different requirements for nutrients. This measurement is important because the plants are growing without soil and depending solely on the nutrients in the added solution. If the perfect amounts of nutrients are used, the plants will grow. It is necessary to measure the pH of the nutrient solution because if the pH rises above 6.5, nutrients will not dissolve in water, and the plants won’t be able to absorb them. Although the pH requirements vary from plant to plant, most plants grow best when the pH is less than 6.5. In reviewing the literature there are too many specifications for this technique and little is written about problems like seed germination and sensitivity to environmental stress produced by high temperatures and humidity. In the second phase, plants were transferred in single cultures (monocultures) and mixed cultures to the Aero Flow hydroponic system. Some variables were tested in order to evaluate which ones are really necessary to develop a viable but simple hydroponic system. The first seeds used in the study, Coriandrum sativum (Coriander), serve to demonstrate that seeds lose viability very fast if not stored properly in a refrigerator or if they are old. Seeds of Puerto Rican Lettuce (Lactuca sativa), Red Lettuce (Teide MTO), Zinnia Thumbelina (Zinnia elegans), Mexican Mint Marigold (Tageles lucida) and Basil Cinnamon (Ocimum basilicum) germinated well and the plants grew all together in the hydroponic system. This demonstrated that it is possible to grow mixed cultures at the same time hydroponically. The results of this research showed that the hydroponic method can be simplified and abundant and healthy crops can be obtained.



Figure 7. Abundant and healthy plants of Coriander sativum harvested by hydroponic technique.

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Figure 9. Coriander sativum packages distributed at the University of the Sacred Heart.

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Figure 18. Abundant and healthy growth of Puerto Rican Lettuce (Lactuca sativa), Red Lettuce (Teide MTO), Zinnia Thumbelina (Zinnia elegans), Mexican Mint Marigold (Tageles lucida), and Basil Cinnamon (Ocimum basilicum) growing together in the AeroFlo system, (mixed cultures).

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Figure 20. Flower of Zinnia Thumbelina (Zinnia elegans) in hydroponic mix cultures growing with Puerto Rican Lettuce (Lactuca sativa), Red Lettuce (Teide MTO), Mexican Mint Marigold (Tageles lucida) and Basil Cinnamon (Ocimum basilicum) growing in AeroFlo system.