Hydroponic Lighting Basics
- Lighting Basics
- What type of garden light should I use?
- How much light do my plants need?
- What are plant nutrients? Do I need plant nutrients?
- What is pH?
- What is Hydroponics?
- What is Aeroponics?
- Do I need CO2 Generation?
- What is the vegetative stage of growth?
- How do I force my plants to bloom?
- How do I propagate or clone new plants?
- How do I germinate seeds?
- What wattage indoor garden lighting system is right for me?
- How much electricity does my light use and how much does it cost?
- What is HID lighting?
- What are lighting spectrum's?
- What is a lumen?
- What are the different components of an indoor garden lighting system?
- What is a ballast and do I need one?
- What is the difference between electronic and mechanical ballasts?
- What is the difference between a High Pressure Sodium (HPS) and Metal Halide (MH) bulb?
- Can I use a MH lamp with an HPS system? And vice-versa?
- What is a conversion lamp?
- Do I need a “horticultural” lamp? Or will any HID lamp suffice?
- Can I use a 1000 watt lamp with a 400 watt ballast?
- Can I use a 430 watt lamp with a 400 watt ballast?
- Should I use a fluorescent lamp? What is a “T5”?
- Does my house need special wiring for my indoor garden light system?
- Do I save electricity if I use a 240 volt outlet instead of a 120 volt outlet?
- How long do HPS and MH lamps last?
- How often should I replace my lamps?
- Should I wear gloves when handling my HID lamps?
1.) Lighting Basics
Choosing the right light is crucial when planning an indoor garden. There are 4 basic choices for artificial light:
- 1. Incandescent Lamps:These types of bulbs are standard household “light bulbs.” Incandescent light bulbs are extremely inefficient and they produce a lot of heat. They produce very little light that a plant can use for growth. Do not use incandescent bulbs for indoor plant growth.Incandescent Lamps
- Fluorescent Lamps:The Fluorescent lamp has become a very popular choice for indoor plant growth over the last decade or so. We recommend using “High-Output” T5 fluorescent lamps only. These types of lamps are 3 to 7 times more efficient than incandescent light bulbs.
- LED Lamps:The LED lamp has been increasing in popularity over the last few years. This technology is still finding its place in the growing world, but it seems to gradually improve over time. The benefit to LED’s is that they use much less electricity, but the trade off is that the light penetration isn’t as good. LED’s are better suited for small grow rooms.
- HID Lamps:Types of HID lamps include High Pressure Sodium and Metal Halide lighting sources. These types of lamps are typically used to light very large areas - Parking lots, gymnasiums, etc. They are the go-to light for professional growers because of their high light output. HID lamps are generally 4 to 8 times more efficient than incandescent light bulbs.
2.) What type of garden light should I use?
- Your ideal light will vary depending on the application. We recommend using high output T5 fluorescent lamps for seedlings, clones, and mother plants. High Outpost fluorescents can also be used for smaller grows. Fluorescents do not have the best light penetration, so we do not recommend using fluorescent lights for large plants.
- We recommend using HID lamps whenever possible. HID lamps have revolutionized indoor gardenning because they are incredibly powerful and they are more efficient than fluorescent systems.
3.) How much light do my plants need?
- We recommend using a minimum of 25 watts per square foot of space. Many growers prefer to double or even tripple this amount. The sun produces an amount of light equivalent to approximately 75 watts per suqare foot
- There is no such thing as too much light, but you do run the risk of scorching your plants if your lights produce too much heat.
- We recommend using the following wattage for the given coverage areas:
- 150 watts — 2' x 2'
- 175 watts — 2' x 2'
- 250 watts — 3' x 3'
- 400 watts — 4' x 4'
- 600 watts — 6.5' x 6.5'
- 1000 watts — 8' x 8'
4.) What are plant nutrients? Do I need plant nutrients?
- Plant nutrients contain the essential chemical elments necessary for efficient plant growth. While it may be true that your plants will grow without supplemental nutrients, your rate of growth will greatly increase with the proper use of nutrients. The rate of growth increases with the use of nutrients because the plant has access to the essential chemicals needed for the proper fascilitation of photosynthesis.
- The major plant nutrients are N-P-K or Nitrogen - Phosphorus - Potassium.
- All nutrients, both granular and liquid, are labeled with the percentage by weight of major nutrients.
- For example, a label that says 10-10-10 means 10% Nitrogen, 10% Phosphorus, and 10% Potassium by weight.
5.) What is pH?
- pH is the measure of how alkaline or acidic your hydroponic nutrient solution is. The pH scale ranges from 0.0 to 14; 0.0 to 7.0 being acidic, 7.0 is neutral, and 7.0 to 14 is alkaline. Most plants excell when the pH is between 6.0 to 7.0.
- If your pH is not within the correct range for your plant, then your plant will absorb less nutrients. The plant becomes "nutrient locked" or "locked out".
- The pH level is measured by checking the activity of hydrogen ions (H+) in your nutrient solution. This can be done with an electronic pH meter, pH test strip, or a chemical pH test kit.
- pH Ranges for Specific Plant Types:
|Basil||5.5 - 6.5||Pea||6.0 - 7.0|
|Broccoli||6.0 - 6.8||Pumpkin||5.5 - 7.5|
|Carnation||6.0||Roses||5.5 - 6.0|
|Chrysanthemum||6.0 - 6.2||Spinach||6.0 - 7.0|
|Cymbidiums||5.5||Tomatoes||6.0 - 6.5|
|Eggplant||6.0||Watercress||6.5 - 6.8|
|Melon||5.5 - 6.0||Zucchini||6.0|
6.) What is Hydroponics?
- Hydroponics is the method of growing plants in a soil-less medium. The roots of a plant are suspended in a medium such as perlite or coco coir. The roots come in director contact with a circulating nutrient solution.
- The benefit to hydroponics is that you can meticulously control the variables that influence your plants rate of growth.
7.) What is Aeroponics?
- Aeroponics is very similar to hydroponics, but it varies in one key aspect: Nutrient Solution deliver method. In an Aeroponics System, the nutrient solution is delivered to the plant roots by some sort of sprayer such as a fogger or mister.
8.) Do I need CO2 Generation?
- Carbon Dioxide, also known as CO2, is an essential component of the photosynthesis process. Plants consume CO2 when producing food during the photosynthesis process. Your plants will benefit from CO2 enrichment the most when the lights are on.
- Proper utilization of a CO2 generator will greatly enhance your plants rate of growth. It enhances the rate of growth by fascilitating a quicker rate of photosynthesis.
9.) What is the vegetative stage of growth?
- The Vegetative Stage of growth is the period when your plants are growing, but not flowering (producing fruit, vegetables, etc.) We recommend using MH or Metal Halide lighting during the vegetative state of growth. Many growers opt to leave the lights on indefinitely during this phase, others prefer to use a 18-6 cycle, or 18 hours on and 6 hours off.
10.) How do I force my plants to bloom?
- Inducing blooming in your plants is easy. Although it varies from plant to plant, generally speaking you must reduce the amount of light that your plants receive. Most growers switch to a 12/12 cycle, or 12 hours on and 12 hours off per day.
- We recommend switching your light to an HPS or High Pressure Sodium bulb during the flowering process.
11.) How do I propagate or clone new plants?
- Producing clones is a simple process that involves removing part of a plant and forcing it to root into a new medium so that it becomes its own plant.
- Using a clean pair of sheers, cut off a branch at a 45 degree angle below at least two nodes. Cutting at a 45 degree angle will increase the surface area for roots to grow, increasing the rate at which your new clones takes root.
- Clip off all lower foilage, leaving only the top growth on the trimming. If the leaves are large then cut them in half so that the plant focuses less on photosynthesis and more on root production.
- Dip the cut end of the clone into a rooting compound for about 30 seconds. Place the dipped end into the medium of your choice. We recommend placing the new cutting in a clone chamber. A clone chamber should contain a heat mat to keep the temperatures elevated, along with a dome to help retain humidity. Maintin moisture and elevated temperatures around 80 degrees Fahrenheit and your clone should take root within a few days. Provide 24 hours of light using a fluorescent bulb or a low wattage Metal Halide lamp.
12.) How do I germinate seeds?
- We recommend storing seeds in a cool dry place. When you are ready to germinate your seeds, simply place them in a warm and wet medium. Maintain an elevated temperature by using a seedling heat mat equiped with a thermostat. 75 to 80 degrees fahrenheit is ideal.
1.) What wattage indoor garden lighting system is right for me?
- There are two primary factors to consider when deciding which light system is right for you. First, consider the size of your grow area. Second, consider how large your plants will be. We only recommend using high output fluorescent lamps if your plants won't be very tall - Fluorescent light penetration isn't as good as HID.
- Generally speaking, you want at least 25 watts of light per square foot. Ideally, you should go with 50 or more. There is no such thing as too much light, but you do run the risk of scorching your plants from the heat produced by your lights if your ventilation isn't adequate.
- The following table can be used as a baseline when determining the proper wattage for a given area:
- 150 watts — 2' x 2'
- 175 watts — 2' x 2'
- 250 watts — 3' x 3'
- 400 watts — 4' x 4'
- 600 watts — 6.5' x 6.5'
- 1000 watts — 8' x 8'
2.) How much electricity does my light use and how much does it cost?
- You can expect your indoor garden light system to increase your electricity bill by 5 to 15 dollars per month or more. Please keep in mind that the exact amount depends on the size of your system, number of hours operated, cost per KWH.
- High Outpost T5 Fluorescents and HID lamps are very efficient, considering how much light they produce. HID's are more efficient than Fluorescents.
- Do not exceed 75% of your breaker box / fuses rated ability. For example, if you have a 20 amp circuit then do not exceed 15 amps. We advise all customers to not exceed 75% of their fuses rated ability as a safety precaution. Contact a licensed electrician if you need to use more electricity than your fuse can handle.
- To calculate how much electricity your light will use, multiply the wattage of the bulb [W] times the hours of operation [H] and divide by . The resulting figure is the number of kilowatt hours of electricity consumed [kW]. [W x H / 1000 = kW] Multiple the killowatt hours consumed times your cost per kilowatt hour. The resulting figure is how much it costs to run your light for the given time period.
3.) What is HID lighting?
- HID lighting is a type of lighting system that is brigher than other types of lighting systems. HID stands for High Intensity Discharge. HID lamp types include High Pressure Sodium (HPS), Metal Halide (MH), Mercury Vapor, and Low Pressure Sodium. HPS and MH lamps are the two primary lamp types used for indoor plant growth.
4.) What are lighting spectrum's?
- Color spectrums are measured using the Kelvin scale. Certain plants grow better under certain spectrums. For example, lamps in the 2700k range are ideal for flowering plants, while lampss in the 6500k range are ideal for vegetating plants.
- Metal Halide (MH) lamps produce light in the 6500k range.
- High Pressure Sodium (HPS) lamps produce light in the 2700k range.
5.) What is a lumen?
- A lumen represents the amount of light produced by a lamp. Lumens are the benchmark by which a lamps ability to grow plants is measured. The brighter the output the better the plant will grow.
6.) What are the different components of an indoor garden lighting system?
- HID and High Output T5 Fluorescent tubes have similar componants. These lighting options consist of a ballast, reflector, socket, and lamp (bulb.) The ballast ignites and drives the lamp.
- Compact Fluorescent Lamps (CFL's) do not require a ballast and be generally be screwed into a normal household light socket.
7.) What is a ballast and do I need one?
- To summarize, a ballast is a transformer that is used to increase the voltage to a level higher than that of the incoming voltage. They also warm up the lamp before ignition.
- You will need a ballast for all HID and Fluorescent Tube lamps.
8.) What is the difference between electronic and mechanical ballasts?
- The primary difference between electronic and mechanical ballasts is the frequency output. Mechanical ballasts produce a frequency of 60 Hz. The frequency produced by electronic ballasts varies from company to company, but generally the frequency produced is about 400x that of a mechanical ballast.
- You will not directly save money from using an electronic ballast. However, you will save money by on cooling costs because electronic ballasts produce much less heat.
- Note: Electronic ballasts are technically more efficient at converting electricity into usable light. However, your powerbill is based on kilowatt-hours consumed, so a 400 watt mechanical ballast will still use the same amount of electricity as an electronic ballast.
9.) What is the difference between a High Pressure Sodium (HPS) and Metal Halide (MH) bulb?
- The primary difference between High Pressure Sodium (HPS and Metal Halide (MH) is the color spectrum they produce.
- Metal Halide lamps produce light that is in the blue / green spectrum, or 6500k range. Metal Halide lamps are ideal for leafy plants or plants that are in the vegetative stage of growth.
- High Pressure Sodum lamps produce light that is in the orange / yellow / red spectrum. High Pressure Sodium lamps are ideal for plants that are actively flowering or producing fruit.
- Many growers will use Metal Halide lamps during the vegetative stage and then switch to High Pressure Sodium lamps during the flowering stage.
10.) Can I use a MH lamp with an HPS system? And vice-versa?
- No. You can not use a regular MH bulb with a HPS ballast. You can not use a regular HPS bulb with a MH ballast. However, you can buy a conversion bulb that works with a ballast other than the one it was designed for.
11.) What is a conversion lamp?
- A conversion lamp is a type of lamp that is able to be used with a ballast other than the one it was originally designed for. For example, a MH conversion lamp will run with an HPS ballast and vice-versa.
12.) Do I need a “horticultural” lamp? Or will any HID lamp suffice?
- We recommend using HID or fluorescent lamps that are specifically designed for horticulture use. Lamps that are specifically designed for horticulture use will produce a color that is more ideal for plant growth and they generally have a higher lumen output. Regular MH or HPS bulb will suffice, but you will definitely see better results with a horticulture specific lamp.
13.) Can I use a 1000 watt lamp with a 400 watt ballast?
- No! The components of the ballast are designed for specific lamp types. Using the wrong kind of bulb could premature failure and it could be a fire hazard.
14.) Can I use a 430 watt lamp with a 400 watt ballast?
- Yes, the components that make up a 400 watt and 430 watt bulb are practically identical.
15.) Should I use a fluorescent lamp? What is a “T5”?
- A T5 lamp provides the ideal spectrum for plant growth. Because of how T5 lamps are designed, they produce light that is nearly perfect for plant growth. The only downside to T5 lights is that they are not as intense as HID lights, so they do not have as good of light penetration. We recommend using fluoresecent lights for mother plants and seedlings.
16.) Does my house need special wiring for my indoor garden light system?
- You may or may not need special wiring depending on the amount and voltage of the lights per circuit. It also depends on the amount of amps your circuit can handle. As a safety precaution we do not recommend exceeding 75% of your circuit breaker / fuses rated ability. So, if you have a 20 amp circuit, avoid pulling more than 15 amps.
- If you are unsure if your electirical system can handle the load then please call a licensed electrician.
17.) Do I save electricity if I use a 240 volt outlet instead of a 120 volt outlet?
- No. Your electricity is billed by wattage consumed, not voltage or current. You may save a little bit of money on cooling costs since 240 volt ballasts draw less current and thus produce less heat.
18.) How long do HPS and MH lamps last?
- The life of your lamps depends on a few variables such as the quality of the bulb, amount of use, how often they are turned on and off, and the quality of the ballast.
- A 1000 watt Metal Halide lamp will last about 12,000 hours.
- A 400 watt Metal Halide lamp will last about 20,000 hours
- Many growers prefer to change their lamps before they burn out because of the loss of lumens and spectral shift that occurs over time.
19.) How often should I replace my lamps?
- How often you replace your lamps is entirely up to you. Some growers prefer to replace them before the burn out because the quality of light produced decreases over time. Other growers simply replace them when they burn out.
20.) Should I wear gloves when handling my HID lamps?
- It is a good idea to wear gloves when handling your HID lamps.
- HID lamp manufacturers do not state that gloves are required when handling your lamps, however we highly recommend that you at least wash your hands prior to handling them. Oil and dirt from your hands can reduce the lights effectiveness.