Hydroponics
is the method of growing plants without soil.

It is a more efficient way to provide water and nutrients to your plants. Soil provides nutrients that must be broken down into a useable form and serves to anchor a plant's roots. Hydroponics uses a wet growing medium and a specially prepared nutrient solution which is readily available to the plant.

In soil, plants must grow a large root system to find food and water. In Hydroponics, food and water go directly to the roots. This enables the plant to spend more energy growing above the surface, producing more vegetation, larger fruit, flowers and vegetables.

Plants grow up to two times faster with larger yields than with conventional soil gardening methods due to the high oxygen levels to the root system, optimum pH levels for increased nutrient and water uptake and optimum balanced and high grade nutrient solutions.

Because Hydroponic root systems are compact in size, plants may be grown closer together. Add to this the fact that there is no weeding, fewer pests and lower water requirements. It is easy to see why home hobbiests, schools and research institutes, as well as commercial growers around the world use Hydroponics.

Hydroponic gardens can be used anywhere as long as sufficient light is provided with ample ventilation. Outdoors, much of the work associated with conventional gardening can be eliminated. Add the proper growing lights and you need not be limited to seasons.

It's quite easy to maintain a Hydroponic system:

Simply add water to the reservoir tank.
Add the proper ratio of nutrients.
Use a timer with the pump and water in cycles depending on the Hydroponic Method and crop type.
Keep the pH at 6.0 to 6.8.
Top off the Reservoir with water when it gets too low.
Change out the solution every 1-3 weeks depending on water consumption.

Our Hydroponic systems
Are shipped direct to you from American Agritech - at their price!
They range from shelf size, room size, or big enough to fill an entire greenhouse. Every system we offer can be purchased as a complete ready to grow kit, or in basic, bare bones kits.

With a little experience you can enjoy fresh herbs, vegetables and flowers year-round!

Hydroponic Methods: Choosing a System

Top Watering Drip Method
The most popular among commercial applications: leaching of salt build up, smaller reservoirs, and less nutrients are just a few of the positive traits of a drip system.

Ebb and Flow
is the method of flooding and draining plastic grow trays. Versatile in application, ideal for seedlings, cuttings, vegetating young plants and for full term crop production. Ebb & flow systems need large reservoirs in order to inhibit salt build up in the growing substrate and to allow ample water volume to flood the grow trays.

Aeroponics
Trays with a lid or a round plastic pipe contain a high pressure mist within, achieving a very high level of oxygen charged nutrient solution for greater nutrient and water uptake. Uses a sequence timer for optimum blasts of solution to the root zone.

Nutrient Film Technique (NFT)
NFT is the method of using shallow troughs with lids where a thin nutrient solution film streams along the bottom of the channels. Ideal for lettuce, herbs, strawberries and flowers.

Can hydroponics support organic gardening?

People are finding that with a little experimentation, they can grow a successful organic, hydroponic garden.  Typical organic products used for hydroponic gardening include bat and seabird guanos, liquified seaweed products, fish based fertilizers and enzyme activators.

What types of plants can be grown hydroponically?

Anything can be grown hydroponically, but some plants prove to be more space efficient. Some plants we suggest are tomatoes, sweet peppers, hot chilies, lettuce, spinach, squash, cucumbers, broccoli, beans, snow peas, herbs and flowers of all types.

Do you really get better yields in less time?

Absolutely. The plants, receiving everything they need, tend to be healthier, faster growing and generally more productive. Expect 30% faster growth with many crops.

Will the flavor compare to my outdoor grown, organic produce?

You bet! This is simply due to the fact that the hydroponically grown plants are getting everything they need, when they need it. Don't be fooled by "hot house" produce grown commercially. The grower's primary concern is shipability and storage, not flavor. When you grow your own vegetables at home, you can expect nothing less than excellent results. Plus, hydroponically grown produce has the added benefit of a longer shelf life.

Will I be using any pesticides? If so, what kind?

Generally, indoor environments demand less pesticides for obvious reasons. Hydroponic growing eliminates soil borne pests, as well. However, if pests do become a problem, one can choose to use insecticide soaps, natural pyrethrums and, in some cases, beneficial insects. These controls will be completely safe to use on edible crops and are also environmentally safe.

Germination

When a seed first begins to grow, it is germinating. Seeds are germinated in a growing medium, such as perlite. Several factors are involved in this process. First, the seed must be active--and alive--and not in dormancy. Most seeds have a specific temperature range that must be achieved. Moisture and oxygen must be present. And, for some seeds, specified levels of light or darkness must be met. Check the specifications of seeds to see their germination requirements.

The first two leaves that sprout from a seed are called the seed leaves, or cotyledons. These are not the true leaves of a plant. The seed develops these first leaves to serve as a starting food source for the young, developing plant.

Growing Medium

Soil is never used in hydroponic growing. Some systems have the ability to support the growing plants, allowing the bare roots to have maximum exposure to the nutrient solution. In other systems, the roots are supported by a growing medium. Some types of media also aid in moisture and nutrient retention. Different media are better suited to specific plants and systems. It is best to research all of your options and to get some recommendations for systems and media before making investing in or building an operation. Popular growing media include:

Composted bark.
It is usually organic and can be used for seed germination.

Expanded clay.
Pellets are baked in a very hot oven, which causes them to expand, creating a porous end product.

Gravel.
Any type can be used. However, gravel can add minerals to nutrient. Always make sure it is clean.

Oasis.
This artificial, foam-based material is commonly known from its use as an arrangement base in the floral industry.

Peat moss.
This medium is carbonized and compressed vegetable matter that has been partially decomposed.

Perlite.
Volcanic glass is mined from lava flows and heated in furnaces to a high temperature, causing the small amount of moisture inside to expand. This converts the hard glass into small, sponge-like kernels.

Pumice.
This is a glassy material that is formed by volcanic activity. Pumice is lightweight due to its large number of cavities produced by the expulsion of water vapor at a high temperature as lava surfaces.

Rockwool.
This is created by melting rock at a high temperature and then spinning it into fibers.

Sand.
This medium varies in composition and is usually used in conjunction with another medium.

Vermiculite.
Similar to perlite except that it has a relatively high cation exchange capacity--meaning it can hold nutrients for later use.

What is the best growing medium? 

There is no clear cut answer to this question. Different mediums work better for different situations and different crops.

. Rockwool will allow the grower an easy set up, since it is pre-formed and modular. It holds a tremendous amount of water and offers a buffer against drying in the case of electrical outages or pump failures. As Rockwool is disposable, it lends itself to quick end of crop clean-up. For starting seedlings and cuttings, Rockwool is without equal! 

. Coconut Fiber is recently becoming more popular. Coconut fiber is the first "organic" medium to offer high performance in modern hydroponic applications. It can also be added into soil mixtures to increase water retention. Coconut fiber holds more oxygen than rockwool and is pH neutral. 

. "Baked Clay" Stone (goes by a variety of names) is a super-fired type of baked clay formed to create a porous, reusable hydroponic medium. It is fairly heavy, which provides secure support for the plants' root zone. This non-degradable, sterile growing medium holds moisture, has a neutral pH and will also wick nutrient solution to the plants' root system. Easy to use. 

Nutrient Solution

In hydroponics, nutrient solution--sometimes just referred to as "nutrient"--is used to feed plants instead of plain water. This is due to the fact that the plants aren't grown in soil. Traditionally, plants acquire most of their nutrition from the soil. When growing hydroponically, you need to add all of the nutrients a plant needs to water. Distilled water works best for making nutrient. Hydroponic supply stores have a variety of nutrient mixes for specific crops and growth cycles. Always store solutions out of direct sunlight to prevent any algae growth.

Osmosis

The ends of a plant’s roots aren’t open-ended like a drinking straw and they definitely don’t suck up a drink of water or nutrients. Science is still seeking a complete understanding of osmosis, so to attempt a full and satisfactory description of all that’s involved in this process would be impossible. However, we can understand the basic osmotic principle as it relates to plants.

First, consider a piece of ordinary blotting paper, such as the commonly used filter for home coffee machines. The paper might appear to be solid. However, if you apply water to one side of it, you’ll soon see signs of the water appearing on the opposite side. The walls of a feeding root act in much the same way. If you pour water onto the top of the filter paper, gravity allows the water to eventually drip through to the bottom side. Add the process of osmosis and water that’s applied to the bottom side drips through to the top.

With plants, this action allows water and nutrients to pass through the root walls from the top, sides, and bottom. Osmosis is the natural energy force that moves elemental ions through what appears to be solid material. A simplistic explanation for how osmosis works, although not 100 percent accurate, is that the stronger ion attracts the weaker through a semipermeable material. So, the elements within the cells that make up plant roots attract water and nutrients through the root walls when these compounds are stronger than the water and nutrients applied to the outside of the roots.

It then follows that if you apply a strong nutrient to the plant roots--one that’s stronger than the compounds inside of the root--that the reverse action is likely to occur! This process is called reverse osmosis. Many gardeners have at some time committed the sin of killing their plants by applying too strong a fertilizer to their plants, which causes reverse osmosis. Instead of feeding the plant, they have actually been dragging the life force out of it.

Understanding how osmosis works, the successful grower can wisely use this knowledge to promote maximum uptake of nutrients into the plants without causing plant stress--or worse, plant death--from overfertilizing. All plants have a different osmotic requirement or an optimum nutrient strength.

Oxygen

As a result of the process of photosynthesis, oxygen (O) is given off by plants. Then, at night, when light isn't available for photosynthesis, this process is reversed. At night, plants take in oxygen and consume the energy they have stored during the day.

Some of the following is excerpted from George Van Pattens' excellent book "Gardening: The Rockwool Book."

Carbon Dioxide

During photosynthesis, plants use carbon dioxide (CO2), light, and hydrogen (usually water) to produce carbohydrates, which is a source of food. Oxygen is given off in this process as a by-product. Light is a key variable in photosynthesis. CO2 - which plants obtain from the air - is the basic and major food of all plant life. In greenhouses or indoor operations, augmenting the natural level of CO2 in the air results in very lush and accelerated growth. It needs to be monitored for optimum levels, but is well worth the investment.

Macronutrients
nitrogen (N), phosphorus (P), and potassium (K)

Plants need around 16 mineral nutrients for optimal growth. However, not all these nutrients are equally important for the plant. Three major minerals--nitrogen (N), phosphorus (P), and potassium (K)--are used by plants in large amounts. These three minerals are usually displayed as hyphenated numbers, like "15-30-15," on commercial fertilizers. These numbers correspond to the relative percentage by weight of each of the major nutrients--known as macronutrients--N, P, and K.

Macronutrients are present in large concentrations in plants. All nutrients combine in numerous ways to help produce healthy plants.
Usually, sulfur (S), calcium (Ca), and magnesium (Mg) are also considered macronutrients.

Micronutrients
boron (B), copper (Cu), cobalt (Co), iron (Fe) manganese (Mn), molybdenum (Mo), and zinc (Zn)

are only present in minute quantities in plants and are known as micronutrients. Plants can usually acquire adequate amounts of these elements from the soil, so most commercial fertilizers don't contain all of the micronutrients. Hydroponic growers, however, don't have any soil to provide nutrients for their plants. Therefore, nutrient solution that is marketed for hydroponic gardening contain all the micronutrients.

Nitrogen

(N) is primary to plant growth. Plants convert nitrogen to make proteins essential to new cell growth. Nitrogen is mainly responsible for leaf and stem growth as well as overall size and vigor. Nitrogen moves easily to active young buds, shoots and leaves and slower to older leaves. Deficiency signs show first in older leaves. They turn a pale yellow and may die. New growth becomes weak and spindly. An abundance of nitrogen will cause soft, weak growth and even delay flower and fruit production if it is allowed to accumulate.

Phosphorus

(P) is necessary for photosynthesis and works as a catalyst for energy transfer within the plant. Phosphorus helps build strong roots and is vital for flower and seed production. Highest levels of phosphorus are used during germination, seedling growth and flowering. Deficiencies will show in older leaves first. Leaves turn deep green on a uniformly smaller, stunted plant. Leaves show brown or purple spots.

Potassium

(K) activates the manufacture and movement of sugars and starches, as well as growth by cell division. Potassium increases chlorophyll in foliage and helps regulate stomata openings so plants make better use of light and air. Potassium encourages strong root growth, water uptake and triggers enzymes that fight disease. Potassium is necessary during all stages of growth. It is especially important in the development of fruit. Deficiency signs of potassium are: plants are the tallest and appear healthy.  Older leaves mottle and yellow between veins, followed by whole leaves that turn dark yellow and die. Flower and fruit drop are common problems associated with potassium deficiency. Potassium is usually locked out by high salinity.

Secondary Nutrients

Magnesium

(Mg) is found as a central atom in the chlorophyll molecule and is essential to the absorption of light energy. Magnesium aids in the utilization of nutrients, neutralizes acids and toxic compounds produced by the plant. Deficiency signs of magnesium are: Older leaves yellow from the center outward, while veins remain green on deficient plants. Leaf tips and edges may discolor and curl upward. Growing tips turn lime green if the deficiency progresses to the top of the plant.

Calcium

(Ca) is fundamental to cell manufacture and growth. Soil gardeners use dolomite lime, which contains calcium and magnesium, to keep the soil sweet or buffered. Rockwool gardeners use calcium to buffer excess nutrients. Calcium moves slowly within the plant and tends to concentrate in roots and older growth. Consequently young growth shows deficiency signs first. Deficient leaf tips, edges and new growth will turn brown and die back. If too much calcium is applied early in life, it will stunt growth as well.  It will also flocculate when a concentrated form is combined with potassium.

Trace Elements

Sulphur

(S) is a component of plant proteins and plays a role in root growth and chlorophyll supply. Distributed relatively evenly with largest amounts in leaves which affects the flavor and odor in many plants. Sulphur, like calcium, moves little within plant tissue and the first signs of a deficiency are pale young leaves. Growth is slow but leaves tend to get brittle and stay narrower than normal.

Iron

(Fe) is a key catalyst in chlorophyll production and is used in photosynthesis. A lack of iron turns leaves pale yellow or white while the veins remain green. Iron is difficult for plants to absorb and moves slowly within the plant. Always use chelated (immediately available to the plant) iron in nutrient mixes.

Manganese

(Mg) works with plant enzymes to reduce nitrates before producing proteins. A lack of manganese turns young leaves a mottled yellow or brown.

Zinc

(Z) is a catalyst and must be present in minute amounts for plant growth. A lack of zinc results in stunting, yellowing and curling of small leaves. An excess of zinc is uncommon but very toxic and causes wilting or death.

Copper

(C) is a catalyst for several enzymes. A shortage of copper makes new growth wilt and causes irregular growth. Excesses of copper causes sudden death. Copper is also used as a fungicide and wards off insects and diseases because of this property.

Boron

(B) is necessary for cells to divide and protein formation. It also plays an active role in pollination and seed production.

Molybdenum

(Mn) helps form proteins and aids the plant's ability to fix nitrogen from the air. A deficiency causes leaves to turn pale and fringes to appear scorched. Irregular leaf growth may also result.

These nutrients are mixed together to form a complete plant fertilizer. The mix contains all the nutrients in the proper ratios to give plants all they need for lush, rapid growth. The fertilizer is dissolved in water to make a nutrient solution. Water transports these soluble nutrients into contact with the plant roots. In the presence of oxygen and water, the nutrients are absorbed through the root hairs.

pH

The pH of a nutrient solution is a measurement of its relative concentration of positive hydrogen ions. Negative hydroxyl ions are produced by the way systems filter and mix air into the nutrient solution feeding plants. Plants feed by an exchange of ions. As ions are removed from the nutrient solution, pH rises. Therefore, the more ions that are taken up by the plants, the greater the growth. A solution with a pH value of 7.0 contains relatively equal concentrations of hydrogen ions and hydroxyl ions. When the pH is below 7.0, there are more hydrogen ions than hydroxyl ion. Such a solution "acidic." When the pH is above 7.0, there are fewer hydrogen ions than hydroxyl ions. This means that the solution is "alkaline."

Test the pH level of your nutrient with a kit consisting of vials and liquid reagents. It is also a good idea to test the pH level of your water before adding any nutrients. If your solution is too alkaline add some acid. Although such conditions rarely occur, sometimes you may have to reduce the level of acidity by making the solution more alkaline. This can be achieved by adding potassium hydroxide (or potash) to the solution in small amounts until it is balanced once again.

The effect of pH on the availability of plant nutrient uptake

Conductivity

Measuring nutrient solution strength is a relatively simple process. However, the electronic devices manufactured to achieve this task are quite sophisticated and use the latest microprocessor technology. To understand how these devices work, you have to know that pure water doesn’t conduct electricity. But as salts are dissolved into the pure water, electricity begins to be conducted. An electrical current will begin to flow when live electrodes are placed into the solution. The more salts that are dissolved, the stronger the salt solution and, correspondingly, the more electrical current that will flow. This current flow is connected to special electronic circuitry that allows the grower to determine the resultant strength of the nutrient solution.

The scale used to measure nutrient strength is electrical conductivity (EC) or conductivity factor (CF). The CF scale is most commonly used in hydroponics.
It spans from 0 to more than 100 CF units. The part of the scale generally used by home hydroponic gardeners spans 0-100 CF units. The part of the scale generally used by commercial or large-scale hydroponic growers is from 2 to 4 CF. (strength for growing watercress and some fancy lettuce) to as high as approximately 35 CF for fruits, berries, and ornamental trees. Higher CF values are used by experienced commercial growers to obtain special plant responses and for many of the modern hybrid crops, such as tomatoes and some peppers. Most other plant types fall between these two figures and the majority is grown at 13-25 CF.

Electro-conductivity (EC) or Conductivity factor (cF) can be expressed as either
millisiemens (ms), cF or parts per million (PPM)
1 mS = 10cF = 700ppm

The pH and electro-conductivity values specified here are given as a broad range. It should be noted that specific plant requirements will vary according to regional climatic conditions, and from season to season within that region.

As a general rule, plants will have a higher nutrient requirement during cooler months, and a lower requirement In the hottest months.  Therefore, a stronger nutrient solution should be maintained during winter, With a weaker solution during summer when plants take up and transpire more water than nutrients.

KNOW YOUR CROP.    Plant EC or cF may vary according to the stage of growth. For example, cucumber prefer cF 20 when establishing, and cF 25 after the first harvest. Between and 7 weeks after first harvest, the optimum cF is 17.

For easy growing reference, plants that share broad groupings of low, medium or high can be grown together using the same nutrient electro- conductivity, providing middle ground cF is adopted.

The nutrient solution should be discarded at regular intervals. Should there be a requirement to flush the growing bed, the system should be flushed with fresh nutrients (run-to-waste) rather than water to avoid starving or stressing plant.