IS 364 Students Build Hydroponic Units


Spring is finally here, and with the ensuing beautiful weather and blossoming flowers begins outdoor lessons in the Spring Creek Recreational Fund’s (SCRF) Urban Garden Classroom (UGC). Garden Educator Jacqui Roytman decided to host her last indoor gardening class with IS 364 students in Laura Saccomanno’s science class. She revisited her previous lessons on hydroponics, reiterating that this is a method that some urban gardeners, especially those without access to a backyard, use to grow plants using only water.

The concept behind hydroponics is that a plant is grown only with inert mediums (Hydroton clay balls, Rockwool, perlite or peat moss) and nutrient enriched water. Roytman provided the sixth grade class with the tools to build three small Hydroponic Window Farm units. “I am going to show you all how to build a window farm, and then we are going to place some lettuce seedlings in each pot,” Roytman said.

A Window Farm is a trendy way urban farmers grow their vegetables and herbs using a small a-mount of interior space. Some people may have access to a pre-made window farm, like the one Roytman brought to the class, which contains a metal wire frame, four pots, a watering chamber and an air pump. This window farm could also be made with recycled water bottles (each bottle is placed upside down in a connected column). Similar to the method Roytman used to make sub-irrigated planters with her students, a person can simply cut holes into the side of a bottle so that the plants can grow. The significant difference in a home-made window farm and a sub-irrigated planter is that an air pump is used to circulate water from the base water chamber to the very top water bottle, trickling down into each connected bottle and then back into the bottom chamber.

Roytman showed the class first how to safely remove the soil from a seedling, so that the roots are fully exposed. She then placed the plant into a basket filled with Hydroton clay balls and small holes in it. This basket is placed into a plastic pot that contains a thin funnel with a hole at the bottom. The students took turns placing four plastic pots onto a thin white metal column. The teens filled up the base water chamber with water, and placed two plastic tubes into it: one was a clear soft tube that hooked into an air pump, and the other was a ridged plastic hook-shaped tube. Once the air pump was turned on, it pushed air from the soft tube into the water chamber. The water in the chamber than shot up through the hard plastic tube and then gently splashed water into the very top plastic pot. Through the small funnels at the bottom of each pot, the water dripped back down to the water chamber, and the cycle continued.

This form of gardening allows a plant’s roots to directly receive nutrients while also being properly aerated in a medium, such as Hydroton clay balls. These interior farms only need natural light and a full water chamber. Roytman explained to the class that soil is not always needed in indoor gardening. In hydroponics, she said that the roots of the plants are constantly watered so that they are receiving all of the proper nutrients. What-ever water is not absorbed by the plants goes back to the base water chamber (or reservoir) and is then pumped back up through the tubes.

To learn how to build your own window farm from plastic bottles check out this YouTube video from the Window Farms Project: ntinue=2&v=PkCuPrsPn_I

Photo by Amanda Moses