What is Hydroponics?
Hydroponics basically means "working water". It is a cultivation of plants in a nutrient enriched solution, instead of soil. Plants feed on basic nutrient salts that are created when biological decomposition breaks down organic matter. Rarely in soil will the conditions be completely balanced. However, a hydroponic system uses water enriched with the same nutrient salts, but is easier to maintain.
Plants are grown in an inert growing medium, although the plant does not receive anything from the medium. The medium is more beneficial if it is able to retain water and also porous enough to allow gas exchange. Types of growing mediums include: sand, perlite, gravel, etc. The plant obtains the nutrients needed from the nutrient solution.
Micro nutrients, such as boron, calcium, cobalt, copper, iron, magnesium, manganese, molybdenum, and zinc, are required for healthy plant growth. Without these nutrients, plants can become wilted, and unhealthy, affecting not just the plant, but the consumer as well.
The Basics and Types of Hydroponics:
The basics of a hydroponic system include a type of growing tray, a reservoir, a time controlled submersible pump, and air pump, and an air stone. The main purpose of the air pump is to add beneficial oxygen into the hydroponics system. Natural or artificial light are also essential to the process. There are six basic types of hydroponic systems: 1. Wick, 2. Water Culture, 3. Ebb and Flow (flood and drain), 4. Drip (recovery/non-recovery), 5. N.F.T. (Nutrient Film Technique), and 6. Aeroponic.
In this system, the nutrient rich solution is drawn into the growing medium from a reservoir by means of a wick. The wick absorbs the solution and draws it up into the tray. This system is very simple to use and operate, but is not ideal for plants that need or use large amounts of water. The wick can only deliver small amounts of solution at a time.
Plants are held in place on a floating platform, usually Styrofoam, with the roots soaking directly in the nutrient solution. Air is supplied by the air stone that bubbles the nutrient solution and supplies oxygen to the roots of the plants. The method is great for growing lettuce, but not for large or long-term plants.
Ebb and Flow
This system floods a growing tray with the nutrient solution by means of a timer controlled pump, programmed to run in multiple intervals throughout the day. Once the tray is flooded and the pump is off, the solution is able to drain back into the reservoir. This cycle continues multiple times a day. Power outages, timer or pump failures make this system vulnerable. Plant roots dry out quickly when the cycles are interrupted. The best solution for this potential harmful problem is to use a growing medium that is able to retain large amounts of moisture.
The nutrient solution is pumped up and dripped onto the base of each plant by small drip lines. In a recovery system, the excess solution runs off and is collected in the reservoir for re-use. The problem with the recovery system is that large changes in pH levels and nutrient strengths mean more adjusting and checking. The non-recovery system does not collect run-off. The nutrient solution is allowed to remain in the medium until it is used completely. This system is less maintenance because the reservoir is refilled with new solution making the pH levels easier to control.
N.F.T. (Nutrient Film Technique)
This system has a constant flow of nutrient solution pumped into the growing tray, usually a tube, flowing over the roots of the plants before draining back into the reservoir. This system usually does not include a growing medium other than air. The plants are supported in the tube by small plastic baskets that allow the roots to dangle down. The danger of this system is if the flow is disrupted, roots will dry out quickly, especially without a growing medium to retain moisture.
The plant roots are air exposed in this system, and misted with the nutrient solution, usually every few minutes. A timer controls this action, but can be potentially hazardous like the N.F.T. system if the mist is interrupted, the roots will dry out rapidly.
Benefits of using Hydroponics:
- Food can be produced in parts of the world with soil that cannot sustain plant life.
- Hydroponic systems eliminate the need for pesticides, since most pests live in the soil. Without pesticides, the Earth’s air, water, and soil will be cleaner. Even the food produced by the plants will be cleaner.
- Water waste is reduced since most systems recycle the nutrient solution.
- NO WEEDS!!
- Hydroponics can save space. Plants can be placed closer together since the roots no longer need to grow and reach for nutrients since the nutrients are brought to them.
What is Aquaponics?Aquaponics is the combination of aquaculture (growing fish) and hydroponics (growing plants without soil). Herbs and vegetables are able to grow and thrive in the same water system as the fish. Fish excrete ammonia in their waste. In high levels, this can be toxic for both fish and plants. Nitrifying bacteria, which lives in soil and water, convert the ammonia to nitrite and then to nitrate. Nitrates are essential for healthy plant growth. Nitrifying bacteria will thrive in gravel in the fish tank as well as the grow bed. The plants will absorb and use the nitrate to grow and thrive, and the water that is returned to the fish tank will contain less nitrates and more oxygen, creating a healthier environment for the fish.
What is Needed?
In order to start an aquaponic garden, you will need: a tank for fish, gravel for the fish tank, a water pump and tubing, an air pump, air stone, and tubing, grow bed, growing medium, and fish and plants of course. Also, you may want to install lighting for both the fish and the plants depending on how the garden is housed (i.e. a garden in a greenhouse should not need artificial light).
What Type of Fish?
The type of fish selected for the system depends entirely on the size. Larger systems can accommodate for larger fish such as tilapia, largemouth bass, and perch. Smaller, at home systems will function with koi and goldfish.
What Type of Plants?
For the most part, leafy greens and lettuce seem to thrive in this kind of system. Herbs such as basil are ideal as well. Other plants are also known to grow successfully such as cucumbers, peppers, melons, tomatoes, and even flowers.
Benefits of Aquaponics:
- Aquaponic systems uses a fraction of water compared to a soil raised vegetable garden because water is re-used and recycled in an aquaponics system.
- Plants are fertilized organically as opposed to chemically, by the natural fish waste.
- By eliminating soil, soil born diseases are also eliminated, as well as weeds, and most pests.
- Aquaponic systems are relatively easy to maintain. Fish need to be fed daily, and water will need to be replenished and refreshed occasionally in the fish tank.