Hydroponics FAQ

What is hydroponics?

Hydroponics, also referred to, sometimes incorrectly, as hydroculture, water culture, nutrient culture or hydro growth, literally means 'water' (hydro) and 'working' (ponics) but, but practically, it means growing flowers, vegetables, fruit, herbs, peppers etc. in water that contains a nutrient solution. Traditional soils are never used.

Although the soil is not required for the plant growth, the elements, minerals and nutrients present in soil are required. An hydroponic system allows absolute control of the nutrients contained in the water.

What are the benefits of growing hydroponically?

There are no soil based diseases.

Growing seasons sometimes become irrelevant.

You have full control over the plants growing conditions.

Hydroponics uses about one tenth of the water needed to grow the same amount of produce using traditional methods.

Hydroponics uses less fertilizer than used to grow equivalent amounts of traditionally grown produce.

Generally speaking, there is a more intensive production in a smaller space.

Can I transfer plants from soil to an hydroponic system?

Absolutely! All you have to do is rinse the roots by gently dipping them in and out of water to remove as much soil as possible. Care should be taken so the plant doesn't go into plant-shock as can sometimes happen. After the roots are thoroughly clear of soil, the plant can be set into whatever medium is to be used and a watering regime can begin for about a week or so to aid swift recovery from transplanting.

Is hydroponics organic?

Not really, but hydroponics is a very pure form of horticulture which uses a fraction of the water and fertilizer that soil-based horticulture uses. There is no need for herbicides in hydroponics because there are no weeds. Most hydroponic growers use integrated pest management or biological control to keep pests and insects from causing damage.

Most hydroponic fertilizers are a mix of premium grade water soluble fertilizers, but some companies have developed organic hydroponic fertilizer that can be certified as 'organic'.

What can I grow with hydroponics?

Nearly all types of plant life will grow hydroponically although there are a few that don't like damp and continuous watering. Most home growers plant vegetables or fruit such as tomatoes, cucumbers, lettuce, peas or herbs etc. These flourish in an hydroponic system.

What does PPM mean?

PPM stands for Parts Per Million and can be used as the measurement of a number of different things. In hydroponics, it is most commonly used to measure the amount of TDS - Total Dissolved Solids in a nutrient solution or how much Co2 is in the atmosphere.

Can I make a business using hydroponics?

Hydroponics can definitely be financially lucrative. If you are already a market gardener or run a small family farm, you're half way there.

In a 10,000 square foot greenhouse, you can grow about 4,0000 - 5,000 pounds of tomatoes every week. Lettuce growers are picking mature heads of lettuce in under 4 weeks, and with 20,000 square feet of growing space, can produce nearly 3,000 heads per week. The cost of establishing a commercial hydroponic greenhouse operation is quite reasonable when considering the potential profit and the intensive volume of high-quality produce that can be grown on a small lot.

How can I tell if my seeds are viable to use?

Fill a glass with distilled water and place your seeds in it. After 24 hours the viable seeds should have sank to the bottom. Seeds that are still floating will probably not germinate.

Do I need a greenhouse?

It is recommended if room is available, but definitely not necessary. A greenhouse provides protection from environmental factors such as heat, cold, wind, rain and insect intrusion. In most climates a greenhouse is recommended. The type of greenhouse and the environmental control equipment varies widely depending on climate. There are many hobbyist growers that use shelves in the hall, or an attic, or unused bedroom etc. This type of growing requires the use of some lighting system.

Can I do hydroponics part time as a hobby?

On a hobby scale, hydroponics has become very popular. It's easy to grow great plants or flowers, it's a 'clean' way of growing, and an indoor hydroponic garden can be used to grow anything from flowers to plants, foliage, herbs, vegetables, fruit, peppers etc. A hobby system can serve as a beautiful show piece and a point of conversation between like-minded people.

What is pH all about?

It's a measure of the acidity or alkalinity of a solution, numerically equal to 7 for neutral solutions, increasing for alkalinity and decreasing with acidity. Nutrients are most soluble at a pH of 6.5. pH stands for Pondus Hydrogeni.

Where do I get the fertilizer and other supplies?

Many companies sell hydroponic kits, fertilizers and supplies. There are still not many hydroponic shops around but most garden centres usually have some hydroponic equipment and there are also many companies that sell online. If you do search for 'hydroponics' you'll see lots of options.

What does EC mean and what is it?

EC stands for Electrical Conductivity. In hydroponics, this is referring to the EC of a solution. An EC meter applies an electrical voltage to the solution and reads the conductivity that is produced from the motion of mineral Ions.

What is the difference between High Pressure Sodium ans Metal Halide?

The difference between these two types of HID (High Intensity Discharge) lights is the colour spectrum that is emitted from each. The High Pressure Sodium bulb emits light that is concentrated in the red to yellow side of the spectrum and is weak in the blue-violet end. While the Metal Halide bulb emits light that is very balanced and contains all the energy peaks at wavelengths of the visible spectrum. Visually the Sodium bulbs will appear very yellowy-orange and the Halide bulbs will appear more bluey-white in colour.

Why do people use Metal Halide lights for vegetables and High Pressure Sodium lights for flowers?

Many people switch between bulbs for different stages of growth for a couple of reasons. First of all, Sodium bulbs have been known to make some plants grow leggy and stretched out because of the yellow to red spectrum that they emit. Metal Halide lights tend to keep these plants tighter with less space between internodes. So some growers use the Metal Halide lights during vegetative growth to keep the structural growth of the plant nice and tight. But they switch to Sodium lights when the plants begin to flower because the Sodium lights produce so much more light than the Halides.

How big does an hydroponics light need to be?

Ideally, you will want to try and achieve at least 30 watts per square foot. So if you have a 4 x 4 area which is 16 square feet and you multiply by 30 watts, you get 480 watts. So for a 4 x 4 area you will need to use at least a 430 watt light. Remember though that the amount of light required will depend on the plants because some plants like lots of light and some don't.

What does HID mean and are HID lights efficient?

HID stands for High Intensity Discharge and is the way the light emits light. HID lights are very efficient compared to standard house bulbs. For example one 1000 watt sodium bulb produces as much light as around 90 standard 100 watt incandescant bulbs.

How often do I have to change the nutrient solution?

There is no specific time when this should be done, although it can be generally planned based on experience. A good rule of thumb is to top off your reservoir with fresh water without any nutrient added. This is because you will lose water to evaporation and plant uptake but the strength of the solution does not necessarily drop with the level of the water. In some cases as the reservoir water level drops the solution concentration actually goes up or gets stronger. This is why you should only add fresh water and then adjust your pH accordingly.

Always try and keep a record of how much water you are putting in the reservoir to top it off and once the amount of water added equals 'half' of the reservoir capacity it is time to change the solution and rinse the reservoir and growing medium. For example, if you have a 20 gallon reservoir and over the course of say, two weeks, you have added 10 gallons of water, then it is time to change your solution!

What is the best temperature range for nutrient solution?

The optimal temperature of a nutrient solution should be in the range of 65 to 75 degrees Fahrenheit. Letting water stand uncovered in a container overnight will help dissipate any chlorine in the water before you add it to the reservoir.

What is the difference between Aeroponics and Aero-Hydroponics?

The roots in an Aeroponic system dangle in the air and are sprayed with nutrient solution. In an Aero-Hydroponic system the roots still dangle, but half of the roots dangle directly into the water and the top half of the roots is sprayed with nutrient water.

This spraying action serves two purposes; it keeps the standing water moving and allows great oxygenation. The Aero-Hydroponic method works incredibly well for rooting cuttings and all other stages of growth as well.