By 2050, the world’s population is expected to balloon to 10 billion, with 80% of people living in big cities. Starting an indoor hydroponic garden requires only a small amount of space, and it can be a fun and rewarding activity that will benefit you in the long run!
To start growing food indoors in hydroponics, you will need: 1) water, 2) liquid nutrient solution, 3) growing medium, 4) net cups or styrofoam boards, 5) water reservoir containers, 6) grow lights, 7) pH meters and EC testers.
In this article, you will learn the many advantages and the few disadvantages of hydroponic food production, along with the 6 main types of hydroponic systems. We will also share 5 food crops you can easily grow indoors. Let’s dive in!
Table of Contents
- 1 What Is Hydroponics?
- 2 5 Advantages of Hydroponic Food Production
- 3 4 Challenges of Hydroponic Food Production
- 4 6 Main Types of Hydroponic Systems [With Pictures]
- 5 7 Materials Needed To Start an Indoor Hydroponic Food Garden
- 6 5 Hydroponic Food Crops You Can Easily Grow Indoors
- 7 Conclusion
What Is Hydroponics?
Coined in 1929 by Professor William Gericke, Hydroponics comes from the Greek word Hydro (meaning water) and Ponos (the god of labor). Together, hydroponics is a horticultural method which relies on water instead of soil to grow plants.
In hydroponics, plant roots are either partially or fully submerged in water mixed with a liquid nutrient solution. A growing medium (such as coir or clay pebbles) anchor down the roots into a net cup or a styrofoam board. The net cups or the rafts float on top of the water reservoir, nourishing the roots as the plants grow.
5 Advantages of Hydroponic Food Production
There are many reasons why more people are shifting to hydroponics in modern times. Here are 5 major benefits of hydroponically growing your food:
1) Food Security
The World Health Organization estimates that around 820 million of the world’s population suffers from hunger. Some people live in deserts and areas with harsh climate conditions. With no access to arable land, these people cannot readily grow their own nutritious food anytime.
Fortunately, hydroponic farming offers a solution to this problem. With hydroponics, commercial growers can safely grow food crops in a controlled environment. Therefore, crop production will no longer be at the mercy of Mother Nature to nourish or destroy at her whim.
2) Saves Space
With the human population skyrocketing each year, we find ourselves rushing to urban centers for work and economic opportunities. Space, no matter how tiny, is now considered a luxury. In big cities, there is barely enough room for gardening.
With hydroponic growing, we are given a chance to grow fresh food without the need for a lot of floor space! In fact, commercial hydroponics systems make it super easy to grow food from your kitchen countertop. To help you choose, we’ve written product reviews to compare the best brands of hydroponic systems in 2022.
3) Less Water Usage
Because most hydroponic production systems efficiently recirculate or minimize the water consumption, hydroponics uses at least 70% less water than traditional agriculture.
In fact, soil gardening drains most of its irrigation water deep underground where it’s no use to any plants or animals. Meanwhile, hydroponic farms ensure that the water is directly being absorbed by plant roots.
4) Environmental Benefits
One of the ways that soil gardening on a commercial scale is harmful to the environment is the possibility of pesticides and other harmful chemicals making their way into a nearby drinking water source.
Since hydroponics removes soil from the picture, you won’t need to deal with weeds or too many soil-based pests. That means we can get rid of the chemical herbicides and pesticides too!
5) Higher Yields
Because root systems in hydroponics have constant access to the water reservoir, nutrient uptake becomes much more efficient. That means, your plants will grow faster, and crop yield will be significantly higher compared to traditional production methods!
Vertical farms, with fresh produce grown on many layers stacked on top of each other, go the extra mile by increasing the yields without requiring more space. This makes it possible for a commercial hydroponic grower to raise huge amounts of organic food even in urban areas.
You can start your own indoor vertical farming with garden towers from Gardyn, iHarvest, Lettuce Grow, and Aerospring. It may be small scale, but you can grow a wide variety of healthy food from the comfort of your home!
4 Challenges of Hydroponic Food Production
Although hydroponics offers promising results, it can also have many disadvantages especially if you don’t have a deep understanding of how it works. Here are some challenges of hydroponically growing food:
1) Start-up Costs: Unlike soil-based gardening, the initial capital outlay required for an indoor hydroponics system will be much higher. You will need to purchase tools and materials to assemble your system. You will also need to allot a monthly budget for energy costs of the grow lights and the mechanical parts of your system.
2) Energy Use: Instead of utilizing natural resources such as sunlight, soil, and outdoor wind circulation, hydroponics will rely on grow lights, a network of pumps and pipes, and portable fans to grow healthy plants. All this energy consumption might have a worrying impact on climate change.
However, it is worth noting that there are studies which compared hydroponic production and traditional agricultural production, and they found that some types of hydroponic systems can actually have a lower overall carbon footprint!
3) Less Room For Error: Hydroponic operation will require a lot of monitoring on your end to maintain a healthy production of plants. You will need to constantly check the water quality, reapply the liquid nutrient solution, regulate temperatures, and keep track of timers for the grow lights, aerators, and draining pumps.
4) Requires Expertise: The whole process requires knowledge not only with the specific hydroponic techniques, but also in terms of how different plant species respond to varying weather conditions (such as light, temperature, humidity). If you plan to grow food on a large scale, you will need to read up on the plant physiology of the crops that you wish to grow.
6 Main Types of Hydroponic Systems [With Pictures]
Below are the major types of systems and methods that you will often read when learning about hydroponics:
1) Wick System
The Wick System is one of the most basic hydroponic culture systems, making it a good choice if you’re just a beginner. Some would even refer to this system as the training wheels of hydroponics. It’s excellent for easy plants like Basil, Chives, Cilantro, Lettuce, Microgreens, Mint, Oregano, Parsley, and Peppers.
The Wick System is based on the principle of capillary action, where a wick absorbs moisture from the mixture below and carries the nutrients upwards towards the growing medium holding the plants.
Wick systems are easy to set up. You’ll just need a rope or a string. It has no moving parts so you won’t need electricity, pumps, and aerators.
2) Deep Water Culture (DWC)
The Deep Water Culture is arguably the most popular setup among growers because it has fast yields and it allows enough space for large plants. With DWC, you can grow Basil, Bell Peppers, Bok Choy, Chard, Collard Greens, Lettuce, and Okra.
Like the system’s name suggests, the roots of the plants in DWC are directly and constantly immersed in water. For this system, it is critical that you install an air pump and aeration stones. Otherwise, the crops may “drown” without enough oxygen.
3) Kratky Method
Like the Wick System, the Kratky Method has a passive system design that doesn’t require moving parts. In fact, you can start with simple mason jars to grow food such as Lettuce, leafy greens, and herbs!
Similar to the DWC system, the Kratky Method suspends crops over a reservoir filled with water and a liquid nutrient solution. What makes them different is the use of mechanical equipment. Kratky systems do not have an air pump for oxygenation. Instead, the roots should be partially exposed to the air so they can “breathe”.
4) Nutrient Film Technique (NFT)
If you have the budget to build a more advanced set-up but don’t have a lot of space to spare, you can go with the Nutrient Film Technique. It is best for plants with small root systems like Broccoli, herbs, and Spinach.
In an NFT system, the main channel which holds the plants is inclined in a slope. This allows the water to drain downwards into a reservoir below, where a series of pumps recirculate the water back up. This cycle nourishes the roots again and again.
Because it’s easy to scale up, the NFT system is commonly found in vertical greenhouses. Common problems in NFT include temperature changes, power outages, and channel clogging. All of these can greatly affect the health of your plants.
5) Ebb and Flow
Also called the Flood and Drain system, the Ebb and Flow method makes use of timers and submersible pumps to flood the plants with nutrient-rich water, and then drain it back to the reservoir in regular intervals.
You can grow Basil, Bell Peppers, Carrots, Chives, Lettuce, Mint, Oregano, Parsley, Radish and Tomatoes in Ebb and Flow systems. However, you will need a growing medium such as Rockwool, perlite, gravel, or rocks to hold your crops upright.
6) Drip System
A Drip Hydroponic System is used in special applications to control the amount of water that reaches the plants at any given time. With a timer, the system slowly pumps the water to the growing media through thin drip lines. As a result, the nutrients can efficiently nourish the plants without flooding the roots.
Drip systems can either be recovery or non-recovery types. In drip recovery systems, the excess nutrient solution is recycled back to the reservoir. You can grow Basil, Bell Peppers, Berries, Lettuce, Mint, and Tomatoes in this type of system.
7) Other Types
Aquaponics is the combination of aquaculture and hydroponics. In an Aquaponic system, you can raise fish and cultivate crops at the same time! The system consists of a reservoir that converts fish waste into fertilizer for plants. Meanwhile, the plants filter the air which gets recycled back into the fish tank in a mutually-beneficial cycle.
Aeroponics, also called Fogponics, nourishes plants by spraying their roots with nutrient formulations instead of immersing them directly in water. This sophisticated method is ideal for the more advanced home gardener. We’ve written an article comparing Aeroponics and Hydroponics to help you out.
According to the National Organic Standards Board which is an advisory committee to the United States Department of Agriculture, all food crops which are produced in hydroponic systems (with the exception of Aeroponics) are eligible for organic certification!
7 Materials Needed To Start an Indoor Hydroponic Food Garden
Now you know about the basics of hydroponics. So what is needed to put all that knowledge into practice? Here is a practical guide to the materials and resources you will need for indoor hydroponics:
Of course, you will need access to clean water. It’s called hydroponics after all, isn’t it? Tap water is usually treated with Chlorine, Fluoride, and other chemicals that might affect the nutrient uptake of your hydroponic crops. Instead, we recommend using distilled water.
You may filter out the chemicals from your tap water by boiling it first or by leaving it out in the open overnight. Applying Hydrogen Peroxide is known to remove chlorine as well. If you don’t want to go through all that hassle, you can simply buy a water filter from Amazon:
2) Liquid Nutrient Solution
Hydroponic nutrient solutions are available in most gardening stores. These products contain all the nutrients essential for plant growth. Make sure to look up which mixtures are ideal for the type of crop you’re growing. Remember to follow the frequency and dosage of application as instructed on the product label.
We wrote an article about using organic nutrients in hydroponics. For popular commercial fertilizers, here are some products you may consider:
3) Growing Medium
In soilless culture, you won’t need soil but you’ll need a growing medium to hold the plants upright. Common substrate options include Hydroton clay pebbles, coco coir, perlite, vermiculture, hemp fiber, horticultural foam, Rockwool cubes, just to name a few.
4) Net Cups or Styrofoam Boards
Net cups or hydrofoam boards serve as the “pots” which hold the base of your hydroponic plants. Mostly, they serve as rafts so the plants can float on water. In some types of systems such as NFT or Aeroponics, there will be no need for net cups or growing media.
5) Water Reservoir Containers
While simpler systems can make use of buckets and jars as a water reservoir, you will need to assemble a series of rails and tubes for bigger projects. The PVC pipe is an ideal material because it is inexpensive, long-lasting, and made of high quality plastic.
You will also need construction tools, machine parts, and other equipment to build a more sophisticated hydroponic system. Here is a video showing you how to get started:
6) Grow Lights
Plants require sunlight to grow. Indoors, you can supplement your crops with artificial light such as fluorescent bulbs, HID lights, and HPS lights. More efficiently, you can go for LED tubes because they don’t heat up too much and they don’t consume too much electricity.
When buying grow lights, make sure you select products that are labeled as full-spectrum instead of the cheap ones consisting only of red and blue light. Also note that regular light bulbs for your home are not the same as grow lights designed for plant growth.
7) pH Meters and EC Testers
The balance of pH and nutrients in the water reservoir of a hydroponic system ultimately affects how plants grow. Take note, different crops require different pH concentration levels!
pH (Power of Hydrogen) measures how acidic or basic the water is. Use a pH meter to check for acidity level. A pH between 0-7 is acidic, while values between 7-14 are alkaline. Most plants prefer a pH reading between 5 to 6.
EC (Electrical Conductivity) is the total measure of salts and minerals in a nutrient solution. Use an EC meter to check your water. The ideal EC reading is between 1.2 and 2.5 S/m2, depending on the current growth stage of the plants.
TDS (Total Dissolved Salts) indicates the strength of a nutrient solution. It is expressed in ppm (parts per million) which is the number of milligrams of nutrients found in every liter of water. Average TDS values for hydroponics are between 600-1000.
8) Other Materials
To avoid fungal diseases and other issues on your plants, you will need to install a portable fan. The constant airflow will regulate extremely high temperatures that can be detrimental to your hydroponic produce.
It is optional but preferable to put up a grow tent for your indoor plants. The grow tent is lined with an inner reflective surface to maximize the light output of your grow lights for your plants. At the same time, you can zip up the tent to shield your eyes from the constant bright lights.
Finally, you will need aeration stones and air pumps to oxygenate the roots of your plants if you’re building a more advanced hydroponic system.
5 Hydroponic Food Crops You Can Easily Grow Indoors
With hydroponics, you can conveniently grow your own fresh vegetables and fruits at home at any time of the year. Here are some common hydroponic food crops you can grow for yourself:
Lettuce is the most popular type of leafy greens cultivated in hydroponics because of its ease of growth and its commercial value.
Grow your lettuce in a cool, dry place and maintain a pH level of 6. Harvesting lettuce usually takes 25-30 days after the seedling is introduced to the nutrient solution.
Tomatoes are versatile fruits that can be used in a variety of dishes. They are one of the most common crops in both hydroponic cultures and traditional agricultural production.
For tomatoes to grow well, you will need to provide them with at least 8 hours of intense sunlight or 16 hours of grow lights each day. A pH level of around 5.5-6.3 is usually recommended, with coco coir as the ideal growing medium.
In another blog post, we’ve written a step-by-step guide to help you grow tomatoes indoors in hydroponics.
Remember Popeye, the guy who ate spinach to become strong? Luckily, this power food can also be grown hydroponically indoors!
Spinach is a little more challenging to grow than other greens, but its nutritional value makes up for it. Spinach is particularly vulnerable to Pythium contamination, so you will need to ensure proper aeration and periodic cleaning.
Spinach grows best at temperatures of 65-70°F during the day and 60-65°F at night. The best pH level is around 6-7.5. It takes around 40 days to harvest Spinach.
Strawberries taste better when they are grown fresh from your own home. Fortunately, it is possible to grow strawberries hydroponically so you can enjoy them all year round!
The best way to grow strawberries is to start with transplants instead of seeds. Maintain the temperature between 65-80°F and the pH level between 5.5 and 6.2. Strawberries will need grow lights for at least 14 hours a day. There should also be an abundant supply of Nitrogen, Potassium, and Phosphorus.
For more detailed information on how to grow hydroponic strawberries at home, you can read our comprehensive guide here.
5) Bell Peppers
Bell Peppers are botanically classified as berries, but we usually group them with Chili Peppers and other spices in the kitchen. They are best grown in Deep Water Culture or Ebb and Flow systems.
Relative humidity for growing bell peppers should be around 55%-60%. Keep the temperatures lower than 93°F to prevent flowers from falling off. Provide artificial light for about 18 hours a day, and maintain a pH level between 6-6.5.
To get more bell peppers, keep pruning your plants so they never grow taller than 8 inches. It will take about 90 days for your bell pepper plants to reach maturity.
When equipped with the right tools and knowledge, starting your own indoor hydroponic garden can be a fun and straight-forward task!
Hydroponics offers many solutions to common problems in agriculture. Skipping the commercial process of food supply chains, hydroponic farming allows farmers and regular citizens alike to grow their local food.
Another benefit of hydroponic food production is food safety. With access to your own fresh organic crops, you won’t need to deal with groceries rotting within days. You also won’t need to worry about which chemicals may have been added to the food you are eating!