There are four main parts to any good HID or fluorescent plant light system and many experts recommend buying all parts together as most components are not interchangeable – meaning most power sources and lamps are specifically configured to work with only one type of light bulb.
- Lamp/hood – The hood is the part that reflects light for maximum efficiency and coverage. Try to stay away from the cone shaped hoods and stick to rectangular or winged hoods for best results.
- Ballast – The power source for your lighting system comes in two different types
- Magnetic – Generally the cheaper option but are heavier, produce less power, run hotter, and may be noisier
- Digital – More expensive than magnetic but produce more power, run cooler, and are virtually silent
- Timer – Any basic grounded (3 prong) timer will do and will allow you to automate your lighting regiment to give your hydroponics garden the optimal amount of light each day.
- Bulb – There are three main types of bulbs you can use in your hydroponic plant light system, each with its advantages and disadvantages
- Fluorescent – Sized based on the bulbs diameter in relation to 1/8th inch. The standard and most popular for indoor growing systems being the T5 which is 5/8ths inch in diameter. Fluorescent lights are ideal for leafy produce such as lettuce and herbs but lack the proper lumen output for fruiting or flowering produce such as tomatoes and peppers.
- HID (High Intensity Discharge) – HID lighting comes in two different types of bulbs and has been used for years in commercial farming and has become the preferred option for home use as well. Although more expensive than fluorescent lighting, HID lights come the closest at reproducing natural sunlight and provide the best option for both leafy produce and fruiting and flowering produce as well. If you’re concerned at the expense of HID bulbs keep in mind that MH bulbs will last for about 1 year of daily use and HID bulbs will last about 3 years.
- MH (Metal Halide) – the perfect all around light, MH bulbs produce a rich blue light that is very similar to full summer sunlight and is the best choice for the vegetative stage of plant growth.
- HPS (High Pressure Sodium) – More efficient that MH bulbs, the HPS bulb produces a red to yellow light and is best used during the fruiting and flowering stage of plant growth.
- *TIP* If you feel the need to choose one bulb over the other, go with the all purpose MH bulb. There are also conversion bulbs – HPS bulbs that run on MH ballasts and MH bulbs that run on HPS ballasts – that allow you to use one ballast for either bulb so you can use an MH bulb during the vegetative stage and switch to an HPS bulb during the fruiting stage.
- LED – Although LED lights have been around for years, they have only recently been introduced to indoor plant light systems. LED systems are able to produce very specific light wavelengths, generate very little heat, and are highly efficient making them a great replacement to HID or fluorescent bulbs. The cost of LED plant lighting has come down dramatically over the past several years and many hydroponic farmers are now switching over to them because of all the advantages making LED plant lights a popular choice. There is some debate over how much LED plant light is required for optimal growth but a good rule of thumb is to have at least 1W per bulb for (anything less is basically just ambient lighting).
How much plant light do I need?
How much HID plant light you will need depends on how big your garden is. As a general rule of thumb when it comes to HID plant lighting you’ll want at least 30-50 watts per square foot of garden space.
|Size of Garden||HID Wattage||Lamp Height||*Cost Per 16hr Day|
|2′ x 2′||175 Watt||12″||$0.14|
|3′ x 3′||250 Watt||12″ – 18″||$0.20|
|5′ x 5′||400 Watt||18″ – 24″||$0.32|
|7′ x 7′||600 Watt||24″+||$0.48|
|*Calculated at $0.05 per Kwh|
T5 fluorescent plant lights are much more straightforward:
- Always keep 4-6” above plants
- Use 40 Watts per square foot of garden space
- Use 1 4’ tube per 2 sq. feet of garden space
- 2’ x 2’ = 2 4’ tubes
- 2’ x 4’ = 4 4’ tubes
For LED plant lights you’ll want to make sure your plant lights have at least 1W/bulb. For instance a 12W bulb with 12 LED lights will have 1W/bulb. Anything less than this will not give sufficient light for your plants to thrive. A 12W bulb with 12 LED lights will be enough for a 1′ x 1′ garden.
If you don’t think you have enough direct sunlight to make your garden flourish make sure you visit our shop at ZeroSoilGardens to pick up all your plant light needs.