Apart from growing hydroponic tomatoes, lettuces have to be the second most popular vegetable to grow using a hydroponic system. They are low maintenance and unlike soil grown lettuces they are less likely to be eaten by pests such as slugs and caterpillars. Secondly hydroponic lettuces are easy to prepare as they will not involve so much washing to remove soil and insects from the leaves.

You can use a variety of different hydroponic systems for growing hydroponic lettuce. Whatever system you use the lettuces spacing should be approximately 6 inches apart as lettuces require plenty of light and you don’t want the lettuce leaves overlapping.

You can grow hydroponic lettuces next to a sunny window or for better results get yourself a compact fluorescent grow light for under $75 with a bulb between 100 and 200 watts.

Good Hydroponic systems for growing lettuce include the Ebb and Flow method, the Nutrient Film Technique (NFT) or just a basic lettuce raft consisting of a shallow reservoir pan, an aquarium air pump and a rigid Styrofoam sheet to hold the net cups in place that contain the lettuce seedlings.

Hydroponic Lettuce Conditions

PH Level: Lettuces prefer a Nutrient Solution PH between 5.5 and 5.8

Temperature: Lettuces prefer cooler temperatures than most vegetables. . An ideal temperature would be between 64 to 70 °F ( 18 – 21 ° C) during the day and 55 to 61 ° F (13 to 16 ° C at night)

Lighting: Compact fluorescents for 14-18 hours a day

Hydroponic lettuce nutrients: For nutrients I recommend Flora Series nutrient solutions put out by GH (General Hydroponics). They are fairly cheap and easy to use and consist of 3 parts (Flora Grow; Flora Micro; and Flora Bloom).

Hydroponic Lettuce Systems

Nutrient Film Technique (NFT): With the NFT system, a thin film of nutrient solution flows through plastic channels, which contain the plant roots with no solid planting media. This can be quite a complex system and not recommended for beginners. The advantage is that less nutrient solution is required.

Ebb and Flow / Flood and Drain system: This is a more simple and reliable method with fairly low initial costs. Pots are filled with a hydroponic medium which anchor the roots and the hydroponic solution floods the system and is allowed to ebb away.

Lettuce Raft System: The lettuce raft works well because it simple and cheap to setup and can be reused. The system just involves a reservoir tank or shallow reservoir pan, an air pump, rigid foam sheet, net cups, air stones, a small bag of LECA, seed starting/rooting plugs, a ¼ compression grommet and of course hydroponic nutrients.

The lettuce raft system is best for a small crop of lettuces where you don’t want to buy an expensive or complicated hydroponic system. The nutrient solution can last a whole growth cycle and the nutrient solution only needs to be topped up with water every time it runs low. It also makes a great choice for school classrooms. See here for an example of a lettuce raft system.

Growing tomatoes yourself can be very satisfying particularly if they are grown hydroponically as they tend to produce higher yields and can be more nutritious and better tasting then those grown using soil. Here is a step by step guide on how to grow hydroponic tomatoes.

1. Buy some tomato seeds, preferably those that produce the smaller variety of tomatoes – they tend to be more compact, smaller and less top heavy. Hydroponic tomatoes can grow high so growing top heavy tomatoes like beefsteak tomatoes can be a bit tricky. You can grow hydroponic tomatoes indoors but be advised that they can grow high depending on the type of tommatoe you intend to grow.

2. You can grow your seeds straight from miniature Rockwool starter cubes. Just use a pencil to create a hole for each seedling.

3. Place the cubes in a plant tray and place a clear, transparent, plastic dome over the plant tray. You can buy a hydroponic propagation dome that enables you to adjust the humidity with adjustable vents. The container should hold in moisture and heat the air around the plant. Try and keep the temperature between 20-25 degrees Celsius or 68 to 77 degrees Fahrenheit and exposed to plenty of light. Like all seeds, tomato seeds require warmth to germinate. You should consider buying a seedling heat mat to keep the seedlings warm by placing the mat underneath the plant tray.

3. Once the seedlings begin to sprout you should move the seedlings into a strong light source, this could be a metal halide or powerful LED light. Keep the seedlings under a strong light source for around 16-20 hours per day.

4. Wait for around 12 days until leaves appear and roots are showing through the bottom of the starter cubes then transport them to a hydroponic system. Tomato plants can grow high so for large plants the drip irrigation system is a good choice. Other systems could include the flood and drain system or the Ebb and flow hydroponic system.

5. You should give tomatoes 13-17 hours of high intensity light in the latter stages with a greater emphasis on High Pressure Sodium lighting, during the bloom and fruit season.

6. Hydroponic nutrients for tomatoes should contain high nitrogen content and a relatively high phosphorous content during the first seven weeks of growth. Phosphorous becomes even more important during the blooming stage of growth so you should consider a blooming type fertilizer high in phosphorus, potassium and other fruit-boosting growth components during this stage– otherwise you can end up with a lot of greenery but less developed tomatoes.

7. Hydroponic tomatoes can grow high so keep them trimmed back and remove any discolored leaves near the bottom of the plant.

What are Hydroponic Air Pumps?

Hydroponic air pumps are used to pump air into a hydroponic nutrient reservoir. Air stones which are inside your hydro tub and connected by an airline tube to your air pump convert the air into small bubbles. This produces oxygen inside your nutrient reservoir which is absorbed into the nutrient solution and utilized by the roots.

Plant root systems require water, nutrients and oxygen. Aerating the roots improves nutrient update and water absorption, increases cell growth and activity. Increased oxygen to the root system has been scientifically proven to increase crop yields. Aerating the water also prevents the nutrient solution from becoming stagnant which can lead to root rot and other problems.

Hydroponic air pumps are cheap and effective way of feeding your plants oxygen. All you need is an air pump, air stones and an air line to connect the air stones to the air pump.

Buying a Hydroponic Air Pump

When choosing a hydroponic air pump a regular air pump designed for an aquarium is all that is required. There are many brands to choose from. Some air pumps are built specifically for hydroponics (General hydroponics), almost all are built for aquariums but they all do much the same thing – they produce air which is then converted into bubbles to oxygenate the water in an aquarium or hydroponic reservoir.

When buying a hydroponic air pump there are a number of factors to consider and specifications listed by the manufacturer. These include:

Open Flow
Open flow or maximum capacity is the maximum flow of air produced without any restriction on the air being drawn by the pump. The Open flow is usually measured in liters or gallons per minute or hour. The amount of air that can be pumped into a hydroponic reservoir is affected by air flow resistance or drag. The air flow or drag is affected by the length of the tubing and depth and pressure of the solution. The greater the PSI of an air pump the more freely the air will flow.

PSI
The PSI of the air pump is sometimes given. This stands for Pounds per Square Inch – the higher the pressure the lower the drag. A higher PSI means the air will flow more freely through the tubing into the reservoir.

Noise Level
Noise Level measured in Decibel (db). Some less efficient air pumps are noisy. This can be a nuisance if the hydroponic system is located indoors. Air pumps produced by Secoh – a Japanese company, are said to be almost silent in operation as well as reliable, efficient and of a high quality.

Maximum Power
Usually measured in Watts, the higher the power the greater the airflow. While some brands and devices are more efficient than others a general rule of thumb is 1 watt for every gallon of nutrient solution.

Life Expectancy
Usually measured in hours this is the estimated time that the device will maintain the specifications given. You can improve life expectancy by replacing parts that get worn or damaged (see below).

Number of Outlets/valves
The number of outlets on an air pump will determine how many Air stones and air line tubing’s you can connect to the air pump. This is useful if you have your plants situated in a number of different buckets or barrels and need an air stone in each container. Some air pumps can have as many as 12 outlets.

Tubing Size
Air pump tubing size is the inner diameter of the tubing which is connected to the air pump vales – usually measured in inches or centimeters.

Cost
The price of an air pump will depend on the brand, wattage, materials and accessories that come with the air pump. You don’t have to spend much on a hydroponic air pump. You can buy a cheap air pump for around $20 – $45 that would be suitable for most indoor hydroponic systems.

Another factor to consider would be whether the air pump is rainproof. If you’re planning on using the air pump outside a rainproof enclosure will protect the air pump from rain or splashes of water.

What is the Best Air Pump Brand?

The following air pump manufacturers produce air pumps that can be used for both aquariums or hydroponic systems:

Hailea, Rena, Tetra whisper, Hiblow, Secoh septic, Alita, Koi, Medo, Ecoplus, Hakko, General hydroponics, Hydrofarm, sunleaves and Danner

General hydroponics – who produce the dual diaphragm air pumps boast that they are the only brand that specifically builds air pumps for hydroponic systems. However any aquarium pump can be used in a hydroponic system.

Secoh septic – a Japanese company, are said to be almost silent in operation as well as one of the most energy efficient hydroponic pumps, it is both reliable, and of a high quality. They claim to have won the best pump in just about every independent review. However because it is a foreign company finding spare parts that need replacing may be more difficult.

Tetra Whisper – the most popular air pump for sale on eBay and they are known for being quite, small and a reasonable price.

Eco-air – another popular brand sold on ebay. It is considered quite, efficient and long lasting with a Controllable variable output on some models.

What Size Air Pump Should I Use?

Some say the more air bubbles the better. However there is only so much oxygen a nutrient solution can hold before it becomes saturated. It is pointless spending the money on an expensive air pump and the running costs that go with that when a smaller air pump will do. The general rule of thumb is 1 watt per gallon of nutrient solution or 1 watt per 3.8 liters.

Air Pump Accessories

Air Stones
Air stones come in different shapes and sizes with the most common being golf ball shaped. They are designed to convert air from the hydroponic pump into a gentle flow of bubbles that rise to the surface. Oxygen is essential to plants and these air bubbles are absorbed into the nutrient solution and used by the plant roots.

Micro-pore diffusers
Micro-pore diffusers are similar but superior to air stones in that they are designed to produce a larger quantity of smaller more prolific bubbles over a larger area. They tend to be more long lasting than air stones and do not clog up so easily. They are made of kiln fired ceramic material designed to not react with nutrient solutions. You can buy single or double micro-pore diffusers.

Air Dividers
Air dividers or port manifolds can be connected to an air pump to create multiple outlets for several air stones or diffusers and therefore provide much greater spread.

Air-line Tees
Similar to Air Dividers/port manifolds they are used for adding an additional line to an existing airline, or making two outlets from one pump outlet.

Airline Tubing
Often made of clear silicon air line tubing fits to your pump or manifold and allows air to flow through easily to the air stone or micro-pore diffuser. You should make sure you use the same length of line to each stone for equal delivery of air into the water.

Air Pump Maintenance

Air pumps require regular maintenance every few months. This can involve replacing diaphragms and filters to keep them running. You should buy an air pump from a manufacturer that you can easily obtain spare parts from. The tetra whispers aps300/aps400 are one of the best hydroponic air pumps on the market and a replacement kit should only cost a few dollars and are readily available.

Make sure you have a non-return valve in the airline to stop the water syphoning back up the air pump and destroying it. This can happen when the pump is positioned below the reservoir.

Valve Blocks
You should replace valve blocks when the pressure fails or when the pump is functioning less efficiently. These valves do wear out over time and this can result in air leads and lower efficiency. You should lengthen the life of these valves by changing your pump’s air filter monthly.

Filters
These filters are usually round and mounted to the bottom of some air models such as the Rena air model. They should be replaced when dirty to avoid damage to the air pump valves and to reduce the chances of the diffusers becoming clogged up.

Air stones
Over time there will be a buildup of salts from your nutrients, these can clog up your air stones. However you should be able to remove the clocked materials using a soft toothbrush.

Good ventilation is essential for healthy plant growth. It is one of the most important factors you need to consider when growing plants within an enclosed space. Ventilating a grow room or grow tent involves selecting the correct size exhaust fan / extractor fan and maintaining a fresh supply of air from outside. This article is designed to help you choose the correct hydroponic fan for your grow room, the best setup and recommended method for installing a hydroponic fan.

Why Ventilation is Necessary?

To maintain adequate grow room ventilation, grow room fans can be used to control humidity, temperature and carbon dioxide levels. A grow room fan or hydro fan within a grow room is essential for a number of reasons. By exchanging, circulating and mixing air, a hydro fan will give you more control over the following:

Humidity
Inadequate ventilation can lead to high humidity and this can result in a number of problems for the plant at various stages of growth. A humidity of 60% RH (Relative humidity) is recommended during vegetative growth and around 40% RH during flowering to prevent flowers or fruits from rotting. It will also help to prevent fungal diseases as fungal spores thrive in humid, stagnant air. Stale stagnant air also provides other airborne pests such as sciarid flies a greater opportunity to infest your grow room. Hot air holds more water vapor so by extracting hot and humid air and replacing it with cooler less humid air, high humidity will become less of an issue.

Carbon Dioxide
Plants need carbon dioxide or CO2 to grow and photosynthesize – this is essential for plant growth. Plants within any confined space will soon use up that carbon dioxide. A hydroponic extraction fan is therefore necessary to maintain high levels of carbon dioxide and ensure a fresh supply of air into the grow room. It is recommended that you should try to replace the air in your grow room at least 20 times per hour or every 3 minutes to maintain a reasonable air quality.

Heat
Hydroponic lights within a grow room can produce a lot of heat. When the lights are on the temperature should range between 21 to 28 degrees centigrade (70 to 82 Fahrenheit). Try and reduce this temperature by about 5 degrees Celsius (9 degrees Fahrenheit) at night as this is important for correct flower maturation. Grow room ventilation using a hydro fan will help maintain the correct temperature. A hydroponic fan speed controller will enable greater control of the temperature as they can be controlled by a thermostat. A fan speed controller linked to a thermostat will enable you to vary the speed of the hydro fan automatically depending on your preferred air temperature.

What Size Fan Should I Buy?

Buying an adequate sized fan for your grow area is important as the cost of a hydroponic fan will largely depend on its size and power. Generally speaking the longer the length of the fan the greater the volume of air that can be extracted at any given minute. However fan designs can vary significantly and you will want to know the CFM value of the fan. The CFM value stands for Cubic Feet per Minute and is the volume of air in cubic feet that can be extracted every minute.

Firstly calculate the area of your grow room or grow tent. Multiply the room’s length by the width by the height. So for example for a 7 foot by 6 foot by 10 foot area, the volume would be 7 x 6 x 10 = 420.

The extraction fan / exhaust fan should exchange the air in the room at least once every three minutes. So simply divide the area in cubic feet by three minutes to calculate the minimum CFM: 420 / 3 = 140 CFM

If you plan to use a carbon air filter (more on that later) multiply by 30%: 140 x 1.3 = 182 CFM .

This is minimum recommended air flow rate and once this has been established you should buy a hydroponic fan with a similar air flow rate. The grow room must include a vent hole to draw air into the room while the hydroponic extractor fan is drawing air out. The vent hole needs to be at least the same size as the size of the extractor. So for example if you are using a 7 inch extractor then the size of the inlet hole should be at least 7 inches but preferably slightly larger to reduce drag. Also air drawn in through the inlet hole needs to be near to the ground were as the extractor fan drawing air out needs to be positioned near the top of the grow room or tent. This will enable better air circulation and mixing and also remove the hot air that tends to rise.

An Intake Fan Plus Extractor Fan

An intake fan can be used in conjunction with an extraction fan to pull air out. An intake fan is the same as an extraction fan but is used to pull air into a grow room instead of removing air. Whether you use an inlet hole or an intake fan, the important thing to remember is that fresh air must be drawn in from outside and the extractor fan should be positioned at the top and preferably on the opposite side of the intake fan. If you chose to use an intake fan and an extractor fan, the combined CFM of both fans must total the CFM required. So if you require 182 CFM, one fan could be 140 and the other 42. However the intake fan should always have a lower CFM and preferably a third to a half of the extractor fan.

Having two fans working together provides better control of humidity and temperature; it creates negative air pressure within the room and prevents smells from escaping back through the ventilations system. You will also discover that the fans will be less noisy and last longer.

If you have to move air to an exterior vent, or move air a distance from an outside wall, you may need to use ducting. Ducting comes in standard sizes that should fit all of your fans and filters. Flexible ducting is easier to work with, but it is important to try and keep it straight. Your ducting should be as short and straight as possible. You should try and avoid bends in the ducting as these will create drag that in turn creates noise as the air moves through. It will also lower efficiency of the grow room fans and may require more powerful fans to compensate.

Buying a Carbon Filter

If the exhaust from your grow room smells you can do something about it. A hydroponic carbon filter can be fitted to your grow room extractor fan. Carbon filters otherwise known as carbon scrubbers will remove almost 100% of the odor from the air before it is extracted. Carbon filters need to be replaced or refilled once in a while.

Normally you would have the following setup: The fan and filter are placed inside the grow room or grow tent and air is drawn through the filter and then the fan before leaving through some ducting to the outside. If the grow area is too small you can get away with having the fan and filter placed outside freeing up space inside the grow room. This way stale air is pulled out of the grow room through some ducting by the fan located outside, the air then moves through the fan, through more ducting and then through the filter before being extracted.

Other Accessories

Fan speed controller: A fan speed controller controls the speed of the fan. If the fan speed controller uses a thermostat it can monitor and regulate the temperature of the grow area depending on the temperature. This is more efficient, reduces noise and prevents the temperature and humidity from falling too high or low.

Acoustic ducting: If the fans are too loud you can use acoustic ducting to reduce the noise of your fans generated by air turbulence. Fix a silencer on each end of your fan to get the full benefits.

Advantages of Using a Hydroponic Grow Tent

The plants are in a more confined area and as a result it is easier to control environmental conditions – such as the temperature, humidity, CO2 levels. This makes it easier to create the optimum conditions required for a specific plant.

If you purchase a grow tent with a reflective silver coating the light and heat is reflected off the interior sides and is mirrored back onto the plant leaves. The confined area and reflective surface saves energy and money.

Grow tents are easy to set up — such as lighting, ventilation, etc. Lights may be hung from the steel-enforced ceiling, and most grow tents also come equipped with ventilation holes so setting up ventilation is an easy process.

With a grow tent there are less problems with pests because there is a barrier between the plants and the outside environment.

Making money with a Hydroponic Grow Tent

Because its possible to control and fine tune the environment within a grow tent you can obtain larger crop sizes and healthier plants than most other environments. A hydroponic grow tent enables you to grow exotic and expensive herbs, fruit or vegetables out of season or under conditions that would normally require a different climate. These plants can be sold yourself or you could always sell them onto restaurants, hotels, farm shops, food halls or private buyers at premium prices.

What to Consider when Buying a Grow Tent

When buying a grow tent the 3 most important factors will be the cost, dimensions and materials. The materials and size of the grow tent are the biggest factors in determining price.

Other Important factors include light and heat leakage, strength of the frame, user friendliness and accessories.

Size and Cost
Indoor grow tents are available in a variety of sizes. Grow tent sizes include the smaller 3×3 and 2×4 foot tents, medium sized 4×4, 4×6, or 4×8 foot, as well as the larger 5×5 and 10×10 foot grow tents.

The cost of a grow tent can vary significantly but you can buy a grow tent suitable for a hobbyist for between $100 to $200. For this price you can expect a decent sized grow tent (at least 4ft x 4ft width x 6ft height) with reflective inner lining.

User friendliness
You want a grow tent that is easy to set up with clear easy to follow instructions. Most grow tents are easy to set up. Here is a video on how to set up a typical grow tent.

Grow Tent Accessories
If buying a grow tent you should also purchase a grow light. A high intensity discharge lamp should be used for this purchase as these are powefull enough to mimic natural sunlight while efficient enough to be cost effecive. Other accessories could include the following:

• an Air Duct Inline Hydroponic Booster Fan
• A Flexible Ducting pipe for the air
• A Hydroponic Carbon Air Filter
• An indoor humidity monitor
• A grow light hanger

You can buy grow tent kits that include all necessary accessories as a single package.

What is the Best Grow Tent on the Market?

When buying a grow tent you should ensure the following standards are met:

• Inner surface should be made of reflective material to retain light and heat (Mylar reflective inner surface etc)
• Be sturdy and strong enough to be moved around and hold a decent sized grow light and/or fan on the bars above the plants.
• Provide good insulation against heat loss.
• Made of non-toxic, non-flammable materials.
• Easy to set up (user friendliness)

The GYO series by LED Wholesalers meet all of these requirements. The Mylar GYO series has a sturdy metal frame structure, is made from 100% reflective silver-colored inner Mylar lining and a tool-free assembly.

Their best selling and highest rated grow tents include the:

• GYO1008 76-Inch x 48-Inch x 48-Inch Mylar Reflective Hydroponic Grow Tent
• GYO1009 60-Inch x 48-Inch x 24-Inch Mylar Reflective Hydroponic Grow Tent
• GYO1001 62-Inch x 36-Inch x 20-Inch Mylar Reflective Hydroponic Grow Tent
• GYO1005A 78-Inch x 36-Inch x 36-Inch Mylar Reflective Hydroponic Grow Tent

Depending on the size, the cost of their grow tents range from about $70 to $120.

Reviews are very positive. Their grow tents are considered good value for money. Very little light leakage compared to other brands (even the more expensive ones). All grow tents leak some light so don’t expect zero light loss.

Here are some reviews of the GYO Mylar grow tents from different buyers:

Great deal for the price!!!

Nice frame, good connectors and I LOVE the vent sleeves as opposed to the holes/fittings.

It is easy to setup…Very sturdy frame.

I researched grow tens for a couple of days before finally deciding on this one…put together without instructions…the vent sleeves are great, I like how they are light-proof…one can actually pick up the whole unit and move to a desired location without falling apart… exactly what I wanted.

This tent is awesome! I research everything for months before I buy…I ended up buying this tent.

The inside is extremely reflective and I was able to easily hang a 600 watt HPS light from the top support bars

For the price it works awesome

If you are looking for a budget HOBBY tent, this is it!

While the vast majority of reviews are positives some negative comments include the following:

My only gripe is the ducting holes are 4 inches and should be larger for this size tent.

Top is a bit weak but I added a thin piece of wood across the top and it holds everything great.

Had to do some mods to make it light tight but it only cost me 11 bucks more

After 3 months of normal use the stitching on the front zipper is pulling out.

The best hydroponic grow light for you will depend on a number of factors. These include the cost of the light, the energy cost of running the light x number of hours a day. The environment that the plant is in and what stage of growth you are trying to facilitate.

Florescent and Incandescent grow lights
While they are cheap to buy they are rather inefficient as hydroponic grow lights. Incandescent and Florescent grow lights are fine for low-light plants where limited results are expected. However the light is of a low intensity and they produce a low level of lumens per watt and are therefore less efficient than High Intensity Discharge Lights (HID) or Light Emitting Diode Grow Lights (LED grow lights). Incandescent lights have a much shorter usable bulb life than high-pressure sodium lights and LED grow lights. They also have approximately six times lower light output per watt of energy consumed than a High Pressure Sodium Light.¹

High Intensity Discharge Lighting (HID)
High Intensity Discharge lighting consists of a lamp, reflector and power supply. They are designed to produce a high output of photosynthetically active radiation (PAR) for the amount of power consumed. It is not just the quality of the light but the quantity that is also important and High intensity discharge lights can produce both.

Commercial growers and some of the world’s premier growers use High Intensity Discharge lights and produce impressive results that would be impossible with conventional florescent and incandescent lamps.

Until recently High Intensity Discharge lighting for horticulture has not been cost effective. As a result of new lighting products by manufacturers like Hydrofarm and Sunlight Supply, lighting costs have been significantly reduced making the use of such lights profitable.

High Intensity Discharge lights are designed to cover the PAR spectrum (Photosynthetically Active Radiation). The wavelengths of light most important for photosynthesis to occur are the red and blue light spectrum, red being 600 – 680 nm and blue being 380-380 nm. These wavelengths are considered the most important for photosynthesis and HID lights cover these spectrums well.

There are two types of HID lamps which emit different colour spectrums:

Metal Halide Grow Lamps
Metal halide lamps emit light at the white/blue spectrum. Metal Halide lamps are best used as a primary light source if there are no other light sources and little or no natural sunlight is available. They consume large amounts of energy but produce significant quantities of light.

Advantages of Metal Halide Lamps (MH)

• Best when there are no other light sources
• Promotes compact vegetative growth
• Best for vegetative growth
• Emit high levels of blue light promoting growth of leafy plants

High Pressure Sodium Grow Lamps (HPS)
High-pressure sodium grow lights have a long usable bulb life and are a much more efficient means of producing light than standard incandescent grow lights. They emit a yellow/orange spectrum of light and have a yellowish glow. They are good when used in combination with other light sources such as weak sunlight during the winter months.

Advantages of High Pressure Sodium Lamps (HPS):

• Work well with other light sources (natural sunlight etc)
• Best for flowering/budding stages of growth
• Ideal for greenhouses and commercial growing applications
• Emit high levels of red light good for flowering and fruiting plants

The Son Agro and Hortilux HPS lamps add an additional 30% blue factor to their spectrum making them more efficient than other HPS lamps for solo use.

You can also buy High Pressure Sodium to Metal Halide conversion bulbs. These can switch from emitting Metal Halide light during vegetative growth then let you switch back to High Pressure Sodium for the flowering/budding stage of growth.

LED Grow Lights
LED grow lights are the most efficient means of producing light for plant growth as the light produced is specifically designed to target narrow wavelengths required for photosynthesis also most of the energy is not lost in the form of heat like other grow lights. LED grow lights have the highest PAR value (photosynthetically active radiation) of all grow lights. The downside of LED grow lights is that they are expensive to buy and while being the most efficient, the cheaper models don’t produce enough lumens to be effective for growing a decent size crop.

Advantages of LED Grow Lights:

• Produce less heat than other light sources which can damage plant and dry up hydroponic solution.
• Much longer bulb life than other lamps. Typical lifetimes quoted are 25,000  to  100,000 hours.²
• Lower energy costs due to higher efficiency
• No costly cooling system required unlike Halide Lights which get hot
• LED grow lights do not contain the harmful mercury-filled bulbs that exist in some other grow lights.
• Powerful LED grow lights have been shown to produce higher yields and vegetative growth

1. Grow Light, Wikipedia
2. Light emitting Diode, Wikipedia

Buying an LED grow light for your hydroponically grown plants can be confusing. There are a number of LED grow light suppliers out there and there are many factors to consider before spending your hard earned money.

PAR, LUX and Lumens

The mistake many people make when buying hydroponic LED grow lights is to buy a LED grow light with a low PAR rate. PAR stands for Photosynthetically Active Radiation, and designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers(nms) that photosynthetic organisms are able to use in the process of photosynthesis”¹ .

Since the Photosynthetically active radiation range occurs within the visible spectrum it is common for the brightness of the light to be measured in lumens or LUX (LUX and lumens are interchangeable). Generally speaking you want an LED light with high lumens but a comparatively low wattage. The light should not get hot as this indicates that the light is not emitting energy targeted at the Photosynthetically active radiation range. Too much heat will result in waste, significantly higher energy cost and a shorter lifetime for the LEDs.The light should be bright enough that it is difficult to look directly at it without squinting.

Nanometers, Spectra Ratios and Watts

The reason LED grow lights have not been commonplace until recently is because it was difficult to find LED lights powerful enough to sustain good growth and within the right wavelength.

The wavelength should be between 400 and 700 nms. When purchasing an LED light this information is sometimes made available and is usually stated in nanometers (nms). Outside of this range and the light will produce wasted energy not used by the plants. Bulbs that get too warm are an indication that they are not emitting energy at the correct wavelengths. This leads to inefficiency and a shorter LED life.

A combination of red and blue wavelengths of light are best for a plants life cycle. Red LED grow lights will be the most important during the flowering stage and blue LED grow lights will be the most important during the vegetative growth. However both red and blue LED grow lights will be important for all growth stages. You should buy a red and blue LED grow light as these will contain both wavelengths – ideal for all stages of plant growth. You can buy red and blue led grow lights on eBay but be aware of low quality and DIY models that are next to useless.

Full spectrum LED grow lights defeat the point of using LED grow lights as they will significantly increase energy costs and are not necessary.

You should aim for a LED light that emits light at 60 to 90 degree angles so that light emitted is not wasted due to a wide dispersion.

Some of the best LED grow lights for sale commercially are the Penetrator LED Grow Lights. They set the standard for grow lights as the Penetrator brand uses cutting edge technology. They claim to produce 3.7x more grams per watt than the competition in independent tests.

The technical specifications for their 126W Penetrator LED Grow Light model which would cover an area of 18” x 30” (46cm x 76cm) is the following:

• Number of LEDs: 126 LEDs each producing 1W
• Gen3 Spectrum: 440nm, 470nm, 525nm, 640nm, 660nm, 740nm
• Spectra Ratios: 75% Red, 10% Blue, 15% Green
• Lens Angle: Intense 60 Degree Lens
• Dimensions: 19″ x 12.5″ x 3.5
• Replaces 250W HID while using 65% less power
• Price: $475.00

You can buy LED grow lights in various wattages. The most common being 90 watt, 200 watt, 300 watt and 600 watt.

Some other popular brands include the following:

• Supernova led grow lights
• Cree LED grow lights
• Advanced LED grow lights
• Illuminator LED grow lights

Guarantee

You should try to ensure a money back guarantee should the LED grow light fail within the first few months.

1. Photosynthetically active radiation, Wikipedia

What are LED Lights?

LED lights are just small light bulbs that can fit easily into an electrical circuit but unlike ordinary incandescent bulbs, they don’t have a filament that burns out, and they don’t get very hot. This means they last a lot longer. They can also be configured to emit light at specific wavelengths thereby making them more efficient for growing plants which require light between 400 to 700 nanometers.

Efficient Means of Producing Light

Thanks to new technology LED grow lights have become the most efficient means of producing artificial light for plant growth. This is because LED grow lights have a high photosynthetic photon flux (area) density for every Watt consumed. What does this mean?

Photosynthetically Active Radiation

According to Wikipedia “Photosynthetically active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers(nms) that photosynthetic organisms are able to use in the process of photosynthesis”¹

PPFD stands for the photosynthetic photon flux (area) density which is the Photosynthetically active radiation emitted per square meter per second. In other words it is how much energy suitable for plant growth emitted every second for every square meter of plant. The higher the PPFD the higher the crop yield as the light can cover a larger area.

Plants only require light energy within a narrow frequency of between 400 and 700 nanometers(nm’s) and other frequencies can even be harmful to a plant. A frequency to high can damage the cells and a frequency too low wont penetrate the plant.

Because Hydroponic LED grow lights can be manufactured to emit light at narrow wavelengths specifically suited to plant growth they are more efficient and don’t require as many Watts to run than other grow lights.

How to Measure Efficiency

The efficiency of a LED grow light is determined by PPFD / Watt of energy. The PPFD per Watt will determine how efficient a light source is at producing photosynthetic active radiation per Watt.
The efficiency of an LED grow light can be expressed as the number of grams of crop produced per watt. However this will vary depending on the plant and other environmental factors.

Since the Photosynthetically active radiation range occurs within the visible spectrum it is common for the brightness of the light to be measured in lumens or LUX.

If these lights are left on 24 hours a day and use a high wattage they can still run up your energy costs. You want a powerful LED grow light that produces a high plant yield but efficient enough that it consumes a relatively low wattage. The following post entitled “Buying hydroponic LED grow lights” discusses factors you need to consider before making a purchase.

1. Photosynthetically active radiation, Wikipedia

Recent advancements in LEDs (Light Emitting Diodes) have produced bright, relatively inexpensive, and long-lasting grow lights that emit only the wavelengths of light corresponding to the absorption peaks of a plant’s typical photochemical processes. Compared to other types of grow lights, LED grow lights are attractive to indoor growers since they consume much less electrical power, do not require ballasts, and produce considerably less heat.¹

Do LED grow lights work

A question many people ask is “Are LED grow lights any good”. The answer is Yes, but only if you are willing buy the more expensive Models and Brands. LED grow lights can work well when used indoors for growing plants hydroponically. NASA is using LED Grow Lights in space right now with great success! These lights are also a lot more efficient than other types of lights. This means lower energy costs and less wastage.

However although the technology has improved significantly within the last few years there are still cheap low quality LED grow lights that should be avoided and you should avoid purchasing grow lights with low LUX or lumens (visible brightness) as these will be pretty useless even for a small plant. Visit the post “Buying Hydroponic LED Grow Lights” for advice on buying a LED grow light for indoor use.

LED grow lights gain their efficiency because their wavelength is concentrated within a spectrum that is ideal for plant growth. They can produce the exact wavelength of light that plants need to grow and direct this light at narrower angles ensuring more of this light reaches the surface of the plants.

Grow Light Alternatives

Hydroponic plant growers can use a variety of different lights for growing plants indoors. These can include flurescent lights, Halide lights, and High-pressure sodium lights (HPS). These lights are costly to run and can damage the plants. For example fluorescent lights emit most of their energy within the UV spectrum. This means they not only inefficient for promoting plant growth and are therefore expensive to run, they can actually damage the plants by overheating them.
Here are some of the advantages of using LED grow lights for hydroponics:

Longer Life Time

Typical lifetimes quoted are 25,000 to 100,000 hours which is significantly longer than incandescent lights that produce more heat and therefore deteriorate more quickly.²

Light Spectrum

LEDs can produce the exact wavelength of light that plants need to grow. HPS lights on the other hand produce distinctive infrared and optical signatures, which can attract pests³

Higher Yields

According to various studies I have seen Hydroponic LED grow lights can produce over twice the yield Watt for Watt than HPS lights.

Low Heat

Hydroponic LED grow lights produce less heat. This allows LEDs to be placed closer to the plant canopy than other lights. Also, plants transpire less, as a result of the reduction in heat, and thus the time between watering cycles is longer.

Low Energy Cost

The lower energy use means lower bills with LED grow lights than HPS grow lights. This is because LED grow lights are able to emit light that contains only the range of frequencies that plants can absorb rather than a large spectrum of light. Also unlike HID bulbs that direct the light at a wide angle, LED grow lights direct light at angles that include 120, 90 and even 60 degree angles thereby giving a smaller coverage so that less light energy is lost.

Do not Require Cooling System

Traditional grow lights such as those that use HPS and Metal Halide become very hot resulting in a need for a cooling system to keep your plants at optimum temperatures which can be costly. While LED lights have built-in fans to cool the base they do not require expensive cooling systems.

Non-toxic

LED grow lights do not contain the harmful mercury-filled bulbs that exist in some other grow lights.

Higher PAR value per watt

LED grow lights are designed to emit light at wavelengths that can easily be absorbed by the plant during photosynthesis.

LED grow lights have a much higher PAR value than other lights such as HPS lights. The PAR value from LED grow lights can be in the thousands. PAR stands for photosynthetic active radiation. It is basically the strength in the lights effectiveness for photosynthesis.

1. Grow light, Wikipedia
2. Light emitting Diode, Wikipedia
3. Grow light, Wikipedia

A video demonstrating how to make a simple homemade hydroponic system:

What you need:
Storage tote tub
Net pots/neti pots
Aquarium/Hydroponic air pump
Sharpie marker pen
Pair of Scissors
Typing paper
Drawing compass
Razor blade or cutting tool
Shipping pallet
Fur strips
Pea gravel
Nutrient solution

Video Transcript:
To build a home hydroponic system you will first need to acquire a storage tote tub. These can be acquired at any wal-mart, Kmart loads and home depot or anywhere storage items are sold.

The most important thing about buying your tote tub is to make sure it has a smooth flat top on it. This is very important for applying the net pots to your system.

The tote tub that we will be using is an 18 gallon tote. The net pots that I am using for this tote tub are 3.75 inches in width. They will need to be that large at least to plant peppers and or tomatoes which is what we will be planting in this hydroponic system.

These net pots I acquired on eBay for about a dollar a piece… Also you will need to acquire two aquarium stones. These are 12 inches each. You will need one for the bottom of each tote tub. I got these for 4 dollars apiece.

The air pump I also acquired on eBay. After paying for the shipping I believe it was $15.00. It is a duel port system, meaning it has two external ports. Here you can see the ports. This is how I was going to lay out the top with the neti pots – their upside down and arranged in the rows that I want. This is going to be an 11 net pot system.

Next I will use a sharpie to draw out where the neti pots make contact with the lid so I know where my holes need to be. You will do this for all the neti pots on the lid. Next I will take one neti pot and trace an outline on a plain white piece of typing paper. I will do the same and draw an outline at the top. I will take a pair of scissors and cut out the circle. Now I want to find the dead centre of this circle – I will fold it twice, once half and then another half so it’s a quarter. Snip out the tip and that will be your dead centre. You can see here the hole.

Next I will place it on the circles I’ve made and will make a small mark so I can use a compass to make an interior circle. There’s the dead centre of the circle and you do this for all the neti pot holes. Next I will use a compass and draw an inner circle about a half an inch inside from the outer circle. First I started using a razor blade to cut out the holes and it proved to be quite tedious so I used a cutting tool I acquired at harbour freight. It worked very fast but it was kind of sloppy. As you can see here it doesn’t produce perfect circles. You will do this for all the holes. Next I came back with a laser blade and smoothed out the edges.

Then you are going to make slit cuts from where the inner circle was to the outer circle. This is so the neti pot will be supported by the half inch lip and it will support the net on the lid while it is soaked into the nutrient solution. You will need to do this for all neti pot holes. Next I bent the tabs downward so that the neti pots fit snug in place. This is how the neti pods look in the tote tub.

Next I acquired a shipping pallet and some 1 inch by 8 foot fur strips. I cut them in half to make them all into four foot lengths as a support structure for the plants as they grow.

To fill the neti pots I’m going to use pea gravel that I picked up at Lowes. A bag can cost about $4.00 Here you can see the support structure that I built using the 1 inch fur strips by 4 foot. This is how the hydroponics is going to be set on top of it and this will be out in the yard so they can get sunlight and as the plants grow you can trail some up on the support structure.

The fertilizer nutrient system you are going to use is very important. You need to make sure that you get a plant food that has micro-nutrients. Here I’m using Peters Professional 20-20-20 and it also has all the micro nutrients because the plants will need all the other of the barium , the iron, the sulphates and everything else it needs to grow because your using the water as the delivery system for the nutrients.

Once we have the support structure set in place we put the tubs on top and we start to fill them up with water from the garden hose. Something I did notice was that as we were filling the tote tubs up, the sides of the tote tubs started to bulge out. As you can see here where the lid is versus where the lid of the tote tub is and its bulging out with the water being filled out. This created a problem because the top would not perfectly seal on top of the tote tub.

Now here you can see the nutrient solution that we added to the water turned into a nice blue colour. We had to add a half of a tablespoon per gallon so we measured it out for 18 gallons per tote tub. As you can see here, here is the aquarium inner pump tubing. I ran through a very small hole that was already naturally in the tote tub and going down into the solution to aerate it. Aeration is very important for your plant fruits.

Here is the air pump which I put on the top of a stepping stone behind the system. I will cover it later with a dishpan so it is waterproof. Now when you’re putting your plants into the neti pots you will want to wash off the root balls of all dirt. Do it gently so you don’t disrupt the root systems and once it gets fully cleaned you want to place the plant dead centre into the neti pots and add pea gravel in around it. You will have to do a lot of estimation here.

Regarding the tote tubs, we solved the problem by using zip ties and a cordless drill . We drilled holes through the lid and into the side lip of the tote tub and then ran zip ties through it. This was a two person operation – one held the lid while the other person drilled and zipped.

The plants as you place them into the nutrient solution will need to be at least 1 inch submerged into the water so that the water can make contact with the neti pot wick up into the pea gravel and into the root system so that the root system will grow outside of the neti pot and down into the nutrient solution. You have to make water contact with the neti pot, that’s very important.

Here is the aquarium air pump with a dishpan on top of the air pump that is sitting on top of the stepping stone and I put a brick on top of it so that the wind won’t blow it off so that waterproofs the pump. We just got a good 3 day rain and it did not get wet.

Here is the back of the system showing the air pump tubing going into the tote tubs and here is what they looked like one week later. The pepper plants have really taken off. They have grown approximately 5 inches in one week. I was pretty amazed at that and they are really bushing out. Here you can see the root systems of the pepper plants just one week later growing out of the pea gravel and out of the neti pot and into the nutrient solution. I was pretty impressed. Thank you for watching.