Hydroponics – What is it?
Hydroponics involves the cultivation of plants in a soil-less medium. It is a modern hydroponic farming practice which is scientifically possible in this generation.Rather the plants grow with the help of nutrient-rich water solution. The plants have their roots exposed to the nutrient solution. The roots are usually anchored by an inert medium such as expanded clay pellets or perlite. The main advantage of general hydroponics is that, the plants grown much faster (up to three times faster) as compared to traditional growing style (that is going plants in a pot with potting mix or growing plants in an outside garden). Also the yield from a hydroponic garden or farm is much high. These advantages have led to many adapting hydroponics. Hydroponic gardens can be organic or inorganic. With organic gardens, nutrients used are fish emulsion, duck manure, and such. For inorganic hydroponics gardens, chemical fertilizers are used.
The hydroponic systems widely used are the wick system, deep water culture, ebb and flow (flood and drain) system, drip system (recovery and non-recovery), N.F.T. (Nutrient Film Technique), and the aeroponics system. Let us look at each of these DIY hydroponics one by one.
N.F.T. (Nutrient Film Technique)
The Nutrient Film Technique is probably the most used hydroponic system. Nutrient Film Technique is an effective and efficient system which minimizes wastage. In this system, a slightly slanted grow tray hold the plants in place while nutrient rich water solution runs through the grow tray. This allows all the plants to have access to water and nutrients. The roots of the plants may be held in a grow medium or allowed to dangle.
Ebb And Flow Hydroponic System
The ebb and flow system is particularly popular among urban growers. With this system, the roots of the plants continuous flood with nutrient-rich water, and then drain. A timer is necessary to control a pump that floods and drains the inert medium which supports the plants roots with nutrient rich water. Many different inert growing media are used such as rock wool, expanded clay pallets and grow rocks. If the timer or pump fails, the roots of the plants can dry out very quickly causing irreversible damage. For this reason, hydroponics gardeners use grow mediums such as coco coir, rock wool and vermiculite because they hold water for long periods.
With this hydroponic system, a pump and series of drip lines drip the nutrient rich water solution on the roots of the plants. The nutrient rich water solution that runs off the roots of the plants may be collected.
Deep Water Culture (DWC)
Deep culture is one of the more popular systems used. It is particular advantages if you intend to grow plants that need a lot of water such as lettuce. With this system, the roots of the plants are left hanging in the nutrient-rich water solution. A media such as Styrofoam is used to keep the plant anchored on top of the nutrient-rich media. An air stone and pump is used to supply air to the plants’ roots. The main drawback of deep water culture is that a very limit amount of plants can be grown with it.
The wick system is a simple system. It is not as widely used as many of the other systems discussed here. This is because this system is unable to supply plants that use a lot of water with enough water. This simple is easy to construct and maintain. With this system, a wick is used to supply nutrients and water to the plants’ roots. Common inert media used to support the plants are perlite, vermiculite, and coco coir.
Aeroponics And Fogponics
These two systems are the most complex and expensive systems to start with. With these systems, mist nozzles/ spray jets mist the roots of the plants with nutrient rich water solution every few minutes. This allows growers to use up to 65% less water and nutrients. Aeroponics is a very successful commercial hydroponic system. You can successfully use this system to start seeds that are almost impossible to start. Commercially this system is mostly used for the production of micro greens, tomatoes, leaf crops, seed potato production, seed germination, and propagation.
As mentioned earlier, you may need to support the plants’ roots. This requires the help of mediums or hydroponic supplies. Here are the most common mediums. The medium you use have to be suitable for the hydroponic system to use.
Expanded Clay Pellets
These are some of the most common medium. Expanded clay pellets are made of baked clay pellets. To make this medium, you roll the clay into small round pellets and heat up to 2,190 °F. The clay expands and becomes very porous. The pellets are allowed to cool. Expanded clay pellets improve aeration and retain water. This enables the plants’ roots to access enough water and nutrients. They can be re-used, making them ecological. Some hydroponic growers prefer not to reuse expanded clay pellets.
Perlite is a common potting mix ingredient. it is also widespread hydroponics medium. Made from volcanic rocks, they are very light in weight and help retain air and water for the plants’ use. Perlite is composed of basalt, pumice, obsidian and granite fused together using a process known as fusionic metamorphosis. Because it is light in weight, water can easily wash away the perlite. Also air and slight movements can shift this medium around. Many hydroponics growers mix perlite with coco coir or vermiculite.
Vermiculite is very much like perlite. They both retain air and water well, although vermiculite does a better job. When added to perlite, vermiculite makes a very good substrate. Vermiculite can also draw water up like a wick. Vermiculite is a mineral that is heated to very high temperatures. This causes them to expand and cool into light pebbles.
Although rock wool have been around for years, many hydroponics growers are moving away from using it. This is because they do not decompose easily and are therefore not good for the environment. Made from molten rock and spun into long thin fibers, rock wool are superb for starting seeds and they retain water very well.
Coco Peat – Coco Coir
Although coco coir is a more recent innovation when it comes to hydroponic systems, they have become very popular, made from coconut husk, they are 100% organic and environmental-friendly. Colonized with trichoderma fungi, coco coir promotes healthy roots development. It also has the ability to provide the plants’ roots with the perfect air to water ratio. It also has the ability to store unused nutrients for later use when the plant needs it. Coco coir comes in many forms with it most used form being coco peat. This has the look and feel of soil.
Gravels are also good support medium for the plant’s roots. They are easy to acquire and economical. You can also reuse them several times. It cannot hold water and therefore unless there is a continuous flow of water, the roots will dry up. They are also very heavy.
Oasis cubes are quite widespread. They are similar to rock wool and have similar uses (for germinating seeds and starting clones) and suitable for starting plants, clones and seeds.
Polystyrene Packing Peanuts
Readily available and inexpensive, polystyrene packing peanuts drain very well and allow for good aeration. They however cannot retain water. When deciding to use polystyrene packing peanuts, nutrient film technique works best. You should not use biodegradable polystyrene packing peanuts since it will turn to slush. Also, there plants can absorb styrene. This can make the products of that plant harmful to humans.
Pumice is one of the minerals that go into the many of perlite. As such, it has some of the advantages of perlite. It is extremely light and commonly we use it in the production of light concrete. This volcanic rock is also a great substrate for hydroponics after crushing it into fine sand. They retain water very well and improve aeration, meaning the plants will grow faster. Since they are lightweight, you may have to combine pumice with other medium.
Starter plugs are mainly for starting plants. Most starter plugs are biodegradable and compose of organic materials. They are important in starting seeds and clones and for the nurturing of clones. With hydroponic gardening, you will very likely use starter plugs to germinate and establish your plants before moving them on to different mediums. You can also use them to start plants for container gardening.
This medium is very similar in nature to gravel. They require cleaning before use and can alter the pH of the environment within which the plants roots are present. This is harmful. Brick shards compose of crushed bricks. Although they are affordable, they are heavy and do not retain water. They also change the pH.
These are biodegradable, and organic. They allow for good drainage but retain little water. Also called PBH for parboiled rice husks, they make good inert substrate.
These are organic and easily available. They will degrade over time but will hold their structure for long. The bad side of this substrate is that, it attracts pest that seek to feed on the wood. Also known as wood wool, they have been around in hydroponics growing for as long as hydroponics itself.
These substrates have very high water and air retention space. Made from glass waste, grow stones are well-known substrates.
Wool sheared from sheep has been found to be a very effective hydroponic substrate. It is suitable for most types of techniques from run-to-waste and recirculating systems. It can retain water and air very well.
One of the advantages of hydroponic gardening is the fact that you use less nutrients as opposed to container and outdoors gardening. Many of you may wonder whether hydroponics uses different types of mineral and nutrients. A hydroponic garden uses the same type of nutrients as other gardening forms use. The main difference is that, the nutrients must be mixed with a water solvent and fed to the plant as opposed to being added to the soil. You can use dry fertilizer or ones that come in concentrated liquid form. You can also go organic, seaweed extract and fish emulsion are two popular organic fertilizers.
There are fertilizers that are better for hydroponics growing. These include fertilizers that mix easily with water. A fertilizer with a ratio of 10-10-10 indicates that 10% of the fertilizer is nitrogen, 10% is phosphorus, and 10% is potassium. The extra 70% is water, small amounts of micronutrients and chelating agents. This ratio is the N-P-K ratio.
Plants absorb these nutrients in very high quantities. The macronutrients are nitrogen, phosphorus, and potassium.
- Nitrogen is an essential macronutrient and is vital for the creation of amino acids, enzymes, and chlorophyll. If you are growing plants for their leaves, a fertilizer with high nitrogen content is essential.
- Phosphorus is an essential macronutrient and is vital for the creation of glucose, which is used to produce energy. If you are growing plants for their fruits, a fertilizer with high phosphorus content is essential.
- The last essential macronutrient is potassium. It is vital to protein synthesis. This makes potassium necessary for root development.
Just because a nutrient is a micronutrients does not mean it is not important, it only means the plant needs this nutrient is small quantities. There are many micronutrients. Some are essential, while others are not.
- Molybdenum is an essential micronutrient that aids in triggering some enzymes.
- Iron is an important micronutrient that aids in the burning of sugar.
- Cooper is an indispensable micronutrient that aids in photosynthesis and plant respiration.
- Manganese is a vital micronutrient that aids in triggering some enzymes.
- Boron and calcium are both necessary micronutrients. Boron combines with calcium to form cell walls.
- Other nutrients include zinc, sulfur, nickel, chlorine, aluminum, silicon, titanium (traces of this nutrient is ubiquitous, so it is rarely added), cobalt (important for the growth of legume), sodium, vanadium, and lithium.
Types Of Hydroponic Nutrients Solution
Inorganic hydroponics solutions differ from soil-based fertilizers because they are not applied to the soil. The soil chemistry influences the extra ingredients added to the hydroponic fertilizers. Hydroponic nutrients solution can be grouped into organic and inorganic or into powdered and liquid forms.
Powdered hydroponics nutrients are less expensive but do not dissolve in water. They also do not include pH buffers. Liquid hydroponic nutrients solutions include pH buffers and dissolves easily in water.
Organic hydroponics nutrients solution is also availble for use. Knowing the exact nutritional composition can be tough. Also, there is always the risk of disease or pathogen transmission. Some organic materials used to provide nutrients for hydroponics grown plants include but not limited to poultry, sheep, horse, cow, goat, horse manure, fish emulsion, kelp meal or liquid seaweed extract, bone meal, blood meal, and bat or bird guano.
Storage And Mixing Of Inorganic Hydroponic Nutrients
- When you have finished using the inorganic nutrients, you need to seal them properly and store them in a cool dry place. Organic nutrient solutions decompose with time unlike inorganic fertilizers.
- Before mixing the fertilizer salt crystal, you should thoroughly crush the salt crystals with a chemist’s pestle and mortar. This is will make it easier to dilute the fertilizer in water.
- With trace element compounds, you should crush them separately and add them to the nutrient solution after you have mixed and dissolved in the macronutrients.
- You should mix and dissolve the salts properly. This will enable the plants to absorb them properly.
Improper Mixing Of Nutrient Solution with Water Solvent
You always run the risk of poisoning your plants, if you do not properly dilute your nutrient solution. And make sure the nutrient solution properly dilutes as per the instructions. It is a bad idea to experiment with dosages, unless you know what you are doing or you will end up killing your plants.
Maintaining The Nutrient Reservoir
The nutrient reservoir holds the nutrient solution. This makes taking care of it of utmost important.
- Before you use the reservoir, be it the first time or not, you should rinse it with tepid water. Then clean out all excess fertilizer salts which can encourage the growth of algae or affect the pH level of the nutrient solution that you add later.
- You should clean out algae, and not allow them to grow. They use up oxygen needed by plants’ roots and reduce nutrient absorption.
- Regular checking of the pH levels of your nutrient solution is essential. You can use chemicals such as pH Up and pH Down to adjust the pH levels of your solution.
- The temperature of the nutrient solution is essential. The temperature in the reservoir needs to be between 65 °F and 80 °F (18 °C and 27 °C)
- You can use electrical conductivity meter, also known as ppm meters to determine the nutrient content of your nutrient solution. Although it is not vital for hobbyist, commercial hydroponic growers need this device.
Air Stone And Air Pumps For Hydroponics
The nutrient solution needs to be aerated and this is where air stones and pumps come into play. The air pump pumps air into the air stone, which dissolved it into the water. There are different brand of air stones and pump out there. It is a vital part of your hydroponic garden.
Grow Lights For Hydroponics
Since hydroponics gardens are normally indoors, you need to provide them with light. Plants cannot grow without light. There are different options to choose from. Fluorescent lights are great for most plants. They come in several intensities for many different types of plants. If you are growing a large number of plants, you will like to go for lights with high intensity such as High Pressure Sodium bulbs, Low Pressure Sodium bulbs, Metal Halide lights, and Mercury Vapor Bulbs. These are High Intensity Discharge (HID) Bulbs.
pH And Hydroponics Plant Growth
The pH of your hydroponic is very important to how plants absorb the nutrients needed for healthy growth and fruition. If the pH is not right, plants will not absorb necessary nutrients even if you provide them with it. pH in simply term is how acidic or alkaline a substance is, where 1 means most acidic and 7 means most basic or alkaline. Water void of any contaminants has a pH of 7 and this is called pH neutral.
Optimal pH Level
When it comes to the growth of your plant, it is important that the pH of the growth environment be between 5.5 and 6.5, with the optimal pH level of most plants being 6.2. This is because plants can optimally absorb nutrients at this level. In addition, this pH level discourages the growth of algae. When you grow your plants in soil or soil mixes, the soil will help regulate the pH to a level that is best for the plants. The likelihood of a pH offset is almost zero with soil gardening. However, with hydroponics, you need to actively regulate the pH of the nutrient rich water solution, which is fed to the plants.
When the pH levels of your hydroponic system is high, nutrients such as copper, iron and nitrogen is not absorbed properly. And when the pH level of your system is low almost no nutrients absorb properly. This makes it absolutely necessary to get the pH right. This is not a difficult process. It is simple and requires little or no previous knowledge.
Determining pH Of Nutrient Reservoir
It is important that you have a way to determine the pH of your nutrient reservoir. You can do this using a pH testing kit or a pH meter. This device is used to determine the pH of your nutrient reservoir. This device is a good investment in the long run.
A pH buffer is necessary to correct pH levels and is absolutely important. Alternatively, you can use litmus paper to determine the pH level of your solution and they are available in most pH testing kits. It is important to keep track of the pH levels of your hydroponic system.