Cheap, energy efficient, durable LED grow lights are becoming more and more popular as home grow lights for both professional growers and for plant enthusiasts. Although certain plants prefer distinctive wave lengths, it is often the best practice to have grow lights that cover full spectrum of the sun light - after all, plants are using that kind of light for rather a long time :)
However, comparing various technologies of grow lights is not that easy.
First of all, there are few things that must be explained:
- there are two types of chlorophyll in plants - chlorophyll A and chlorophyll B. Chlorophyll A absorption peaks are at 430 nm and 662 nm wavelengths and 453 nm and 642 nm for chlorophyll B. Chlorophyll B in plants helps in increasing the light absorption range and is not as abundant as chlorophyll A.
- chlorophyll is not the only chemical compound in plants that actually absorb light. LED grow lights often use several LED colors covering these peaks. In fact, many LED grow lights use colored LEDs, white LEDs and infrared LEDs in order to cover needed wavelength - for example, some LED grow lights can cover 9 to 11, or even more, different bands: 430-440nm, 450-460nm, 470nm, 610-615nm, 620-630nm, 650-660nm, white, IR, UV etc. Strictly speaking 'white' is not a narrow band (wavelength), but requires different LEDs. Note: operating IR (infrared) and UV (ultraviolet) LEDs look as if they are NOT working, but they simply emit light in IR/UV bands that can't been seen by human eyes.
- when comparing grow light efficiency, many people look just at produced lumens per spent watt of energy. In that terms, LEDs with 18-22 lumens per watt (and these numbers are improving with every new generation of LED grow lights) are not as efficient as fluorescent grow lights producing 90-110 lumens per watt. However, there is something called Photosynthetically Active Radiation (PAR). It is the measure of the actual light energy that is of value to the plants to promote growth, flowering and bearing fruits. Relative PAR value of LED grow lights is higher than any other light source.
- LED grow lights are 'cold' lights since they operate at rather low temperatures, around 40-60°C, and because of that they can be positioned close to the plants. This takes advantage of the inverse square law for light - meaning that more light end up on the plants and not wasted around them. Also, since LEDs operate on low temperatures, they can be even positioned among the leaves (individual LEDs), not only above them, leading to stronger plant growth and bearing more fruits. This is very important when growing berries indoors, because plants can be tightly planted. Note: LED grow lights require cooling, smaller light systems use passive cooling, while larger ones require active cooling using small fans - no matter how you set these lights up, don't block the airflow, or your expensive LED light system could malfunction soon!
- initial price of LED grow lights is the highest among most popular grow lights (fluorescent tubes, High Pressure Sodium (HPS) lights, High Intensity Discharging (HID) lights etc), however, they are solid state devices and last for a long time, up to or even more than 50.000 - 100.000 hours (for decades!).
LED growing lights come in various sizes, shapes, strengths, spectrum numbers etc. They are often designed to fit standard E27 light bulb socket, with light housing acting as heat sink. Also, LED grow lights are often available as LED panels or even strips of various dimensions, making them suitable for grow shelves, efficiently utilizing area designated for indoor berry garden.
Next table shows short description and comparison between popular LED grow lights. Feel free to follow links for Amazon reviews and recommendations (all links in table open in the new window).
|LED Growing Lights||Photo||Description|
|Mudder E27 5W LED Grow Light P20||
E27 socket, 5W LED is energy saving grow light, with low heat and low power consumption, long service life and high luminous efficiency. Wave band ranges are 445-450nm (blue) and 660nm (red).
Optional: 5W, 10W, 12W, 20W, 45W.
5W LED grow light - approximately equal to 30W incandescent light.
|Advanced Platinum Series P300 300w 12-band LED Grow Light||
12-band spectrum - from the UV to the IR light. Selectable 'Veg' and 'Flower' switches. 2 built in cooling fans.
Covers 3 feet x 2 feet (91x61 cm) from 18 inch (46 cm) height.
Average power consumption: 93W Veg, 180W Flower. Replaces 400W HPS grow light.
Advance Platinum Series is available in 150W, 300W, 450W, 600W, 900W, and 1200W.
This is NOT cheap LED grow light, but what you pay is what you get!
|GalaxyhydroTM 300W Full Spectrum LED Grow Light||
9 bands: 430~440nm, 450~460nm, 610~615nm, 620~630nm, 650~660nm, white, IR (730nm) , UV (380~400nm), 470nm.
LED grow light has UV (ultraviolet) and IR (infrared) LEDs - they are not so brighter than others, but it's normal and have special function in plant growing and flowering. This is not quality problem.
|King 300w Full Spectrum 360-870nm LED Grow Light Panel||
Dimensions: 12.2x8.26x2.36 inches (31x21xx60 cm), coverage area about 3 x 3.5 feet (0.9 x 1.05m), producing 11000 lm, lux ~13000lux/1m or 10000lux/1.5m, Par ~380umol/1m or 200/1.5m.
Also available: 450W, 900W, 1200W.
Note: For more Amazon LED grow lights choices, click here.
Light Timers - Automation
LED grow lights often come with built-in, easy to manage, timers. These timers automatically turn light on and off - don't forget that many plants to grow properly require periods of darkness, especially for proper flowering. Therefore, when growing berries indoors, keep light on for not more than 17-18 hours, so that plants have at least 6-7 hours. The optimum light and dark ratio depends on the species and variety of the plants - if you are not sure about this, keep the light on for 16-17 hours and your berries will do fine.
Combining automatic light timer with water pump timer creates growing system that requires almost no daily care, except for one thing - hand pollination.
LED Grow Lights vs Fluorescent Grow Lights
Personally, the ONLY 'competition' for LED grow lights are light systems based on the fluorescent tubes, especially fluorescent tubes like T5 and perhaps T8.
T5 light tubes measure 16mm (5/8") in diameter and are known as one of the most efficient fluorescent tubes available on the market. They produce around 100-110 lumens per watt of spent energy, last 20.000-25.000 hours, come in different lengths (mostly as 2 and 4 feet tubes), operate slightly warmer than LED lights and are much cheaper than LED lights (5-10 dollars/euros per tube/bulb).
LED Grow Lights vs High Pressure Sodium (HPS) Grow Lights
HPS grow lights are very efficient - they produce 140 lumens per watt of spent energy, but they operate at higher temperatures (around 500°F or 260°C) and must be kept away from the plants. Also, their initial costs are somewhat lower than costs of LED grow lights, but HPS lights initial costs are higher than fluorescent lights' costs.
Since they produce much heat during operation, they often require additional cooling, especially during summer. During winter, they provide both light and warmth to the growing plants.
HPS are part of High Intensity Discharge (HID) group of lights that generally operate between 500 and 600°F (260-315°C) and produce at least 125-130 lumen per watt of spent energy. However, all these systems require the bulbs, sockets, reflector and a ballast, not to mention additional cooling of growing area during warmer months.
Call me biased, but for growing berries indoors, mostly strawberries and similar berries, one wants to plant as many plants as possible in available area and wants to cut initial and running costs as much as possible.
LED grow lights are still being perfected, but keep in mind that LED grow lights from the '70s are still working! Many people complain that certain LED grow lights are good for green vegetables (lettuce and similar plants, including herbs) and are not as good for fruits and plants like tomatoes, eggplants and similar. Such LED lights often lack certain wavelengths, or they are too weak - red light, 600-640nm, is very important for flowering and bearing healthy fruits.
If you like DIY activities, make two shelves, one with full spectrum LED grow lights and one with fluorescent tubes (T5 or good Compact Fluorescent Light (CFL) highly recommended) and test your berries during at least one full season.
Long Story Short - for newbie indoor growers, there are all-in-one systems based on full spectrum LED grow lights. Feel free to test them.
Fluorescent lights, especially CFLs are still very good option for grow lights - if low initial costs are important, forget any other grow light system.
However, if you don't mind higher initial costs, full spectrum LED grow lights is a way to go, especially if one can find them on a sale :)