In Part 2 we talked about High-Intensity Discharge lights in the form of Metal Halides and High Pressure Sodium lights. In this article we will continue with the lighting topic and have a look at fluorescent lighting.
By Sarah Pick
We are all acquainted with fluorescent lighting as the majority of us will have it in our home or workplace. The main difference concerning this popular style of fluorescent lighting and that employed in hydroponics is the presence of phosphor. The fluorescent grow lights in hydroponics consist of a blend of phosphor which supports photosynthesis in plants.
These lights are different to HID lamps as they are considerably cooler and can be arranged within a few inches of the plants. Consequently the plants get increased light but it also means that the lights need to be shifted higher as the plants develop. A number of gardeners remedy this drawback by fixing the lights to a pulley mechanism.
Like HID lights fluorescents come in both colour frequencies from “cool white” which performs in the blue spectrum and “warm white” which works in the red spectrum. These can be employed in the different stages in growth from vegetative to flowering periods. The lower powered fluorescents are suitable for leafy crops like herbs, lettuce and starting off seedlings. While the higher powered fluorescent lights are more suitable for fruits and flowering plants.
There have been advances in varieties of fluorescent lights with the introduction of T5’s and CFL (compact fluorescent lights).
T5’s have high-powered tubes which generate a far brighter light when compared with regular fluorescent grow lights. Both of these lights give out more heat but still are cool enough to be positioned several inches above your plants.
CFL’s are smaller models of fluorescents and yet provide more power like the T5’s. These are especially useful if you are limited by space as they are engineered to have an increased surface area of bulb so light is not decreased. They are available in the blue and red colour spectrum and a lot like the T5’s use little electricity in contrast to HID bulbs. The downside is that T5’s and CFL’s are more expensive than normal fluorescent grow lights. Which I imagine you would guess as they produce more light.
There are many advantages to fluorescents compared to HID’s:
• Use a lot less electricity
• Lower cost
• Give out far less heat
• Good for propagation
• Straightforward to manage
But with all things there are disadvantages:
• Are required to be in close proximity to the plants to give productive light
• Do not deliver the same amount of yield that HPS bulbs do
• May not be appropriate for all varieties of crop
• The tubes are delicate and need to be handled with care
Fluorescents might be beneficial to use when beginning to use hydroponics because they are low in cost. There are some good stands with built in pulley systems on the market that make having hydroponics in the home easy to maintain. It is all down to personal choice and reliant on the sorts of fruit or vegetables you want to produce.