We talk about hydroponics and aquaponics around here like it’s NBD. Jolene suggested that I do a hydroponics and an aquaponics 101 for the classroom for those of you who are new to this gardening technique. Hydroponics provides a great opportunity for hands on, authentic learning in the classroom. Since hydroponics deals with nutrients only and aquaponics deals with fish, I will start with the less complex of the two: hydroponics. We’ll first take a look at the nutrients used in hydroponics. Further posts will describe the procedures you can use to set up a hydroponics system in your classroom. After we describe the hydroponics system we will move to the aquaponics system for your classroom. Yes, it is possible to do both in the confines of a single classroom!
Hydroponics is the use of chemical nutrients to grow plants in a medium that does not contain soil. The nutrients used in a hydroponics system contain the typical N-P-K (Nitrogen, Phosphorus, and Potassium) that we are taught that all plants need for growth. But the nutrients also contain numerous micro-nutrients needed for healthy plant growth. If you think that you can use the fertilizers from a garden center, think again, fertilizers like Miracle Grow are not suited to hydroponics because they lack the micro-nutrients. So while your plants may grow, they will not do as well as if you used the proper nutrients for a hydroponic system. But don’t fret, I’m now going to tell you where and how to get these nutrients very inexpensively!
The three nutrients I have used are Epsom salt (Walgreens), calcium nitrate 15.5-0-0
(Amazon) and Tomato 4-18-38 (Amazon). You should also be concerned about the pH of your water. Where I live, in Wisconsin, our pH is about 8.0. Plants like a pH of about 6.5-7.0, so I use a chemical called pH down in my hydroponics tank which holds about 25 gallons (Brew and Grow).
If you have children growing individual plants and your water is alkaline, I have them add a drop of lemon juice to each of the containers every day or two.
Watch for hydroponics 101.2 methods in a future blog post.