5 Ways to Start Hydroponic Gardening

Growing Plants Without Soil

Hydroponically grown lettuces.
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Hydroponics is a form of gardening that uses no soil, but instead grows plants in a solution of water and nutrients. A hydroponic system can grow plants and vegetables faster and year-round. Plants grown this way usually yield more, require less space, and conserve soil and water. This system is an ideal solution if you are an apartment dweller who does not have an outdoor gardening plot. Throughout the growing process, you will need to control several factors, such as lighting, water quality, air circulation, and more.

Three systems are suitable for beginners: the wick system, the water culture system, and the ebb and flow system. More advanced systems include the nutrient film technique and the aeroponic system. The easiest plants to start with are greens like lettuce, spinach, Swiss chard, and kale; herbs like basil, parsley, oregano, cilantro, and mint; and fruiting plants like tomatoes, strawberries, and hot peppers.

The Wick System

The wick system is the simplest system mechanically, as there are no moving parts or electrical components. This system is not ideal for water-hungry plants like lettuce or tomatoes, as they may use up the nutrient solution faster than the wick can supply it. This system works best for microgreens, herbs, and peppers.

Project Metrics

  • Working Time: 30 minutes
  • Total Time: A few days (to change or add water)
  • Material Cost: $50 ($100 if you need a grow light)

What You'll Need

Equipment/Tools

  • Drill or screwdriver (optional)
  • Grow light (optional)

Materials

  • Bucket or basin for water reservoir
  • Water
  • Hydroponic fertilizer (dry or liquid)
  • Cotton or nylon cord
  • Growing medium
  • Seedling
  • Growing tray

Instructions

  1. Set up a water reservoir. Create a reservoir filled with water and nutrients. This reservoir will be beneath the tray holding your plant and growing medium.
  2. Connect wicks to the growing tray. You will need to connect one or two wicks through holes in the bottom of the growing tray. If you need to make holes in the growing tray, use a drill or screwdriver. The wicks will soak up water from the reservoir and draw it up the wick to the growing medium in the tray.
  3. Set up a growing tray. The growing medium, containing a seedling, is set above the water reservoir. Use a medium that will not drain too fast and will utilize the capillary action of the wick most effectively, such as vermiculite, perlite, and soilless mixes.
  4. Set up a light fixture, if necessary. If using natural light, skip this step. Otherwise, set up a light fixture above the growing tray. If using incandescent light bulbs, set it 24 inches from the plants. LED and fluorescent lights are not as hot; place them 6 and 12 inches, respectively, from the plants.
  5. The growing medium, containing a seedling, is set above the water reservoir. Use a medium that will not drain too fast and will utilize the capillary action of the wick most effectively, such as vermiculite, perlite, and soilless mixes.

Water Culture (Raft) System

A water culture system is another simple system to set up. In this system, the plants are placed in a styrofoam platform that floats on top of the reservoir with the nutrient-enriched water. Unlike the wick system, you will need to aerate the water in this system. This system is best for growing leaf lettuce, but very few other plants grow well in this system.

Project Metrics

  • Working Time: 45 minutes
  • Total Time: Add water-fertilizer solution as needed
  • Material Cost: $50 ($100 if using grow light)

What You'll Need

Equipment/Tools

  • Drill, rotary tool, or Exacto knife (optional)
  • Grow light (optional)
  • Air stone and pump

Materials

  • Bucket or basin for water reservoir
  • Water
  • Hydroponic fertilizer (dry or liquid)
  • Styrofoam sheet
  • Seedlings in net pots

Instructions

  1. Set up the water reservoir. Create a reservoir filled with water and nutrients. This reservoir will be beneath your plant and floating plant raft. This system is suited for water-hungry plants like lettuce, but it is not recommended for more long-lived plants, like tomatoes.
  2. Aerate the water. The most common and inexpensive aeration system is an air stone and pump. The air stone, the same as a bubbler found in home aquariums, is placed in the water and connected to an air pump outside the reservoir. The pump pushes air through the stone, which blows out tiny bubbles to distribute oxygen through the water.
  3. Set up your growing raft. Cut a floating styrofoam platform to fit the top of the reservoir and cut holes to insert net pots. Net pots are plastic containers with perforated bottoms that contain a growing medium (coconut coir, perlite, clay balls) and seedlings. The roots will need to be in contact with the reservoir water.
  4. Set up a light fixture, if necessary. If using natural light, skip this step. Otherwise, set up a light fixture above the growing tray. If using incandescent light bulbs, set it 24 inches from the plants. LED and fluorescent lights are not as hot; place them 6 and 12 inches, respectively, from the plants

Drip Systems

The most widely used type of hydroponics systems in the world, drip systems are simple: a timer controls a submersed water pump that drips nutrient solution onto the base of each plant via a small drip line. A "recovery" drip system collects and reuses excess solution, while a non-recovery system need a more precise timer to ensure the plants get enough nutrient solution, while keeping runoff to a minimum. We'll focus on the non-recovery system to keep it simple.

Project Metrics

  • Working Time: 45 minutes
  • Total Time: Add water/fertilizer as needed
  • Material cost: $50 ($100 if using grow light)

What You'll Need

Equipment/Tools

  • Drill
  • Grow light (optional)
  • One submersible water pump
  • Air pump
  • Electronic timer

Materials

  • Grow tray
  • Container for water (opaque, so that bacteria and algae don't grow in it)
  • Tubing
  • Drip emitters, one per plant
  • Seedlings in pots
  • Growing medium, such as coco coir/perlite mix
  • Water
  • Hydroponic fertilizer

Instructions

  1. Set up a water reservoir with aeration. A container filled with nutrient-filled water is positioned under the growing chamber. Add an aeration bubbler in the reservoir to oxygenate the water.
  2. Connect a submersible pump to tubing. The reservoir solution is pumped to the plants vIa tubing from a submersible pump tube in the reservoir. The drip emitters are aimed at the plant's roots in a growing chamber.
  3. Connect the pump to an electronic timer. Set the timer to automatically irrigate the plants several times each day.
  4. Set up the growing chamber. Place the seedlings in pots in a growing tray, with a drip emitter aimed at the roots of each plant.
  5. Set up a light fixture, if necessary. If using natural light, skip this step. Otherwise, set up a light fixture above the growing tray. If using incandescent light bulbs, set it 24 inches from the plants. LED and fluorescent lights are not as hot; place them 6 and 12 inches, respectively, from the plants.

Ebb and Flow System

An ebb and flow system, also called the flood and drain system, is slightly more complex in design but is extremely versatile. This system works by flooding the growing medium with a water-nutrient solution, then it drains back into the reservoir.

Project Metrics

  • Working Time: 1 hour
  • Total Time: Refresh the water-fertilizer solution every week
  • Material Cost: $75 ($125 if using grow light)

What You'll Need

Equipment/Tools

  • Grow light (optional)
  • Two tubes (fill tube and drain tube)
  • One submersible pump
  • Electronic timer

Materials

  • Bucket or basin for water reservoir
  • Water
  • Hydroponic fertilizer (dry or liquid)
  • Growing tray
  • Seedlings in net pots

Instructions

  1. Set up the water reservoir. The reservoir is placed directly below the flood tray's stand with the water and nutrients. You can use the same water for about a week at a time, making sure to renew the nutrients every time you change the water.
  2. Connect a fill tube and drain tube. Connect the reservoir to the tray via a fill tube and a drain tube. The fill tube attaches to a submersible pump with a timer, which controls the flow of water up into the flood tray. The drain tube allows gravity to pull the water back into the reservoir after flooding so that the water can be reused.
  3. Connect a submersible pump and timer. A submersible pump with a timer allows for a lot of control in this type of system. You can customize the length and frequency of watering based on your plant's needs.
  4. Set up the flood tray. The plant tray or flood tray is a large, shallow container on a tall stand. Plant your seedlings in perforated pots filled with a growing medium like perlite. The pots that your seedlings are in should be about twice as deep as the flood tray.
  5. Set up a light fixture, if necessary. If using natural light, skip this step. Otherwise, set up a light fixture above the growing tray. If using incandescent light bulbs, set it 24 inches from the plants. LED and fluorescent lights are not as hot; place them 6 and 12 inches, respectively, from the plants.

Nutrient Film Technique

The nutrient film technique uses a water-nutrient solution that constantly flows in a loop from a reservoir through a growing tray, where plant roots are suspended in air and absorb nutrients as the solution flows by. This system makes the ebb and flow system a continuously flowing system, never taking periodic breaks.

Project Metrics

  • Working Time: 1 hour
  • Total Time: Refresh the water-fertilizer solution every week
  • Material Cost: $85 ($135 if using a grow light)

What You'll Need

Equipment/Tools

  • Drill or rotary tool (optional)
  • Grow light (optional)
  • Air stone and pump
  • Two tubes (fill tube and drain tube)
  • One submersible pump

Materials

  • Bucket or basin for water reservoir
  • Water
  • Hydroponic fertilizer (dry or liquid)
  • Tube or PVC pipe to fit the seedlings
  • Seedlings in net pots

Instructions

  1. Set up the water reservoir and aeration. The reservoir is placed directly below the flood tray's stand with the water and nutrients. You will add an aeration bubbler in the reservoir to oxygenate the water.
  2. Connect the fill tube, drain tube, and pump. Connect the reservoir to the tray via a fill tube and a drain tube. The fill tube attaches to a submersible pump, which controls the flow of water up into the flood tray. The drain tube allows gravity to pull the water back into the reservoir after flooding so that the water can be reused. Unlike the ebb and flow methods, you do not need a timer, since it is continuously pumping the water.
  3. Set up the growing tray. Instead of a flat tray, this method uses tubes or channels for the grow tray. This tubing makes it easier to set it at an angle and to make sure that the nutrient solution flows directly to the roots. You can use a round tube or PVC pipe with holes drilled to fit the net pots or seedlings.
  4. Set up a light fixture, if necessary. If using natural light, skip this step. Otherwise, set up a light fixture above the growing tray. If using incandescent light bulbs, set it 24 inches from the plants. LED and fluorescent lights are not as hot; place them 6 and 12 inches, respectively, from the plants.

Aeroponic System

An aeroponic system is a more complex hydroponic method. Plant roots are suspended in air and misted every few minutes with a water and nutrient solution. It is a highly effective method but one that requires sophisticated pumps and misters. If the equipment malfunctions, the plant roots can dry out and die quickly.  

Project Metrics

  • Working Time: 1 hour
  • Total Time: Refresh the water-fertilizer solution every week
  • Material Cost: $100 ($150 if using a grow light)

What You'll Need

Equipment/Tools

  • Drill or rotary tool (optional)
  • Grow light (optional)
  • Air stone and pump
  • One tube (spray tube)
  • One submersible pump
  • Sprayer/misting head

Materials

  • Bucket or basin for water reservoir
  • Water
  • Hydroponic fertilizer (dry or liquid)
  • Tube or PVC pipe to fit the seedlings
  • Seedlings in net pots

Instructions

  1. Set up a water reservoir with aeration. A container filled with nutrient-filled water is positioned under the growing chamber. Add an aeration bubbler in the reservoir to oxygenate the water. This reservoir also acts as a catch basin for misted droplets of solution.
  2. Connect a submersible pump and tube to a mister or sprayer. The reservoir solution pumps to the mister or sprayer vIa tubing from a submersible pump tube in the reservoir. The sprayer will be aimed at the plant's root in a growing chamber.
  3. Set up the growing chamber. Similar to the nutrition film technique, you will set up tubes or channels for evenly suspending each seedling's roots.
  4. Set up a light fixture, if necessary. If using natural light, skip this step. Otherwise, set up a light fixture above the growing tray. If using incandescent light bulbs, set it 24 inches from the plants. LED and fluorescent lights are not as hot; place them 6 and 12 inches, respectively, from the plants.

Hydroponic Growing Tips

  • Most edible plants require at least six hours of sunlight each day; 12 to 16 hours is better. Make sure to put your lighting system on a timer, so the lights turn on and off at the same time each day.
  • The best lighting for a hydroponics system is high-intensity discharge light fixtures, which can include either high-pressure sodium or metal halide bulbs. Halide bulbs emit a more orange-red light, which is great for plants in the vegetative growth stage. T5 is another type of lighting used in hydroponic grow rooms. It produces a high-output fluorescent light with low heat and low energy consumption. It is ideal for growing plant cuttings and plants with short growth cycles. 
  • Ideal temperatures are between 68 and 70 degrees Fahrenheit. High temperatures may cause plants to become stunted, and if the water temperature gets too high, it may lead to root rot.
  • The ideal humidity for a hydroponic grow room is from 40 to 60 percent relative humidity. Higher humidity levels—especially in rooms with poor air circulation—can lead to powdery mildew and other fungal problems. Consider a humidifier or dehumidifier to adjust the relative humidity.
  • Your grow room should also have an ample supply of carbon dioxide; your plants will grow faster. The best way to get carbon dioxide to your plants is to make sure the room has a constant flow of air. If necessary, invest in a fan or air circulation equipment to improve the airflow.
  • Hard water that contains a high mineral content will not dissolve nutrients as effectively as water with lower mineral content, so you may need to filter your water if it is high in mineral content.
  • The ideal pH level for water used in a hydroponic system is between 5.8 and 6.2 (slightly acidic). If your water doesn't meet this level, chemicals can be used to adjust the pH into the ideal range. 
  • The nutrients (or fertilizers) used in hydroponic systems are available in both liquid and dry forms, as well as both organic and synthetic. Use fertilizers that are designed for hydroponic gardening; do not use standard fertilizers. The fertilizer should have the main macronutrients—nitrogen, potassium, phosphorus, calcium, and magnesium—as well as micronutrients iron, manganese, boron, zinc, copper, molybdenum, and chlorine.