Hydroponics is a method of growing plants without the need for soil. This might sound strange at first but plants actually only need nutrients, light, and carbon dioxide to grow and be healthy. Hydroponics provides a more compact and efficient space to grow plants. Hydroponic gardens for vegetables are becoming popular due to the demand of space within cities and the demand for fresh food. You can grow anywhere using efficient hydroponic solutions.
Choosing a System
Choosing a system can be difficult and is very situational to each scenario. Some different types of hydroponic systems include: Aeroponic, Drip system, Ebb and Flow system, Nutrient Film Technique, Water Culture system, and Wick systems. Are you completely lost? Most of these do the exact same thing in different designs. The common things in which you will need are a water reservoir, pH balance, a pump, a growing tray or housing, and nutrients for your plants. The water will also need to be aerated in order for the plants to grow properly. Other things that are nice to have include a quick water evacuation, and a nutrient reservoir. A brief description of the different systems below.
Aeroponic – System with misting based delivery method for watering.
Drip System – System in which water and nutrients are delivered via water dripping at a constant rate.
Ebb and Flow – An inert medium that the plants grow through is flooded periodically.
Nutrient Film System – A shallow stream of water is recirculated through the plants roots.
(Deep) Water Culture – A plant suspended in water that is constantly being aerated.
Wick System – Utilizing capillary action to deliver water to the plants.
Hydroponic growing. Image via Flickr user luvjnx.
Peas or Carrots?
Choosing your crop is one important factor in deciding the layout of your setup. How much light will your plants need? How much water will be needed? What sort of minerals do your plants grow well in? We want to provide the optimal conditions for your plants to prosper. If your plant has large root growth then you might want a deep water culture system. This will enable the plant to receive plenty of water without obstruction in the growing tray. Tomatoes prefer a slightly acidic soil to grow in. They prefer a 6-6.8 oh the pH scale which is what most vegetables grow optimally in. Plants need minerals to grow as well. If you look on a fertilizer bag normally you will see a number that looks like “5-5-10”. This is the percentage of Nitrogen, Potassium, and Phosphorus. This is very important to all plant life and will determine how delicious your produce is.
Inert growing media. Image via Flickr user Ben Yanis.
Indoor Growing Solutions
So you need to grow indoors? If you noticed, I said that plants need light, not necessarily sunlight. There are many solutions in which plants can grow with artificial light and if done properly better than outdoor hydroponic gardens. Although solar panels are not completely out of the question, it takes a little more engineering throughout your house to make them work. For some, it might just be easier to plug your pump and lights into a wall.
Efficiency
A system can only be improved if you know where energy is being wasted. Each garden is different because of the situational variables, however a few simple precautions can ensure an efficient system. A vacuum pump within a closed loop system can provide the best results in efficiency for water circulation. Gravity would be doing most of the work. If it is possible for you to grow your garden outside or in a transparent greenhouse then electricity is negligible in your equation for cost. Using reflective materials such as Mylar can increase the Intensity of light in your garden. Mylar can be costly and flat white paint will reflect as much as 90% of the light back which is much more cost effective.
Lighting
Choosing lighting for your garden can be a daunting task for some. Intensity, Duration, and Color (temperature) of light are all things to consider when making the decision to purchase lights for your garden. Intensity is not just a measurement of quantity in lumens, but of heat your plants will receive from that light. Duration is the amount of time your plant will need to grow. Some plants will need as little as 3-4 hours of direct light daily.
Temperature controls are specialized for growth of the plant. Plants have different stages in their life cycle just as we do. The balance of warm temperature and cool temperature light enables the plants to grow strong and flower. Metal halide, high Pressure sodium, and high intensity fluorescent bulbs all have different color temperatures, power consumption, and cost to maintain. MH bulbs produce mainly blue while HPS bulbs produce more red/orange spectrum of light. MH and HPS bulbs cost the most and need to be replaced every 18 months. They also consume the most electricity. Light-emitting-diodes or LED, have been new to the grow light market but are popular because of the ultra-low wattage rating. They also come in warm and cool temperatures. The cost can be 2-3 times more expensive initially, however they have the longest lifespan of any grow light. High intensity fluorescent bulbs come in both blue and red/orange spectrum and have relatively low wattage in comparison to HPS or MH. They are the cheapest of all grow lights.
Lily Pad Arduino microcontroller. Image via Flickr user SparkFun Electronics.
Automation
Automation in growing plants has become standardized by the agricultural industry. Many farmers in the United States use large scale irrigation methods to water entire fields evenly throughout the season. A microcontroller can be programmed to automate everything about the system. It can even notify you when something has gone wrong. Solar panels can be introduced to power the microcontroller, which uses very little power, to potentially eliminate the need for electricity in your grow space. Sensors with a microcontroller can make your garden exponentially more efficient. Soil moisture, temperature, and even light levels can be monitored.