LightWave T5 Overview Advice FAQ LightWave T5 lighting has proved to be a revelation for plant production. From propagation through to bloom, now there is truly a fluorescent alternative for all stages of plant growth. Light for living things T5s used in propagation will produce even growth and bushiness with short internodes and thick stems. However, unlike other fluorescent lights T5s can be used throughout the growth cycle to produce mature plants of great quality. The LightWave Advantage The perfect colour temperature for plants. Reduced heat output allows closer positioning to plants. Ideal for use in enclosed spaces – less heat build-up. T5 fluorescent tubes maintain lumen output longer and generally cost less than HID lamps. LightWave T5 fixtures take up minimal space and can hang vertically or horizontally. LightWave T5 will support both vegetative growth AND fruiting and flowering. Closer = brighterThe inverse square law states that light projected onto a surface is inversely proportional to the square of its distance from the source. Basically this means that the closer the lights are to the plant the better, but by a much bigger amount than intuitively expected. Halve the distance and quadruple the light. Technically-speaking, the inverse square law only applies to “point sources” of light. Since fluorescent lamps are long thin tubes, it’s more apt to consider these as “line sources”, which behave in a slightly different way. However the fact remains that fluorescent lights – even the powerful T5s – can be placed very close to the plants. The extra raw power of the T5 is considered adequate to overcome the deeper penetration of HID lights. Limited headroom The T5 tubes are mounted inside the reflectors so the total depth of the fitting is quite minimal. This, coupled with the closer mounting possible for T5’s, allows for plant production where headroom is limited and is perfect for use on shelving units. What are Lightwave T5 lights? T5 is a particular type of high-output fluorescent tube, far brighter than the older standard T8 type lights and powered by a special T5 ballast. Why are they better than normal fluorescent tubes? T5s are substantially brighter than standard fluorescent tubes and can be tuned to deliver specific colour balances suitable for plant production and fish-keeping. Therefore, T5s are presented here as a replacement for standard fluorescents in propagation systems – with not so many T5s needed achieving better results – and for HID lights in general plant cultivation. By using T5s fewer tubes are needed than before, and will deliver much more light power over plants or fish. Do they have any advantages over metal halide and sodium lighting? Fluorescents are always described as “cooler” light sources and by comparison with HID lights that is certainly true. However T5s generate more light than the older tubes and there is inevitably some heat given off. The law of physics is a tough taskmaster. However T5s certainly are cool, in comparative terms, and can be placed much closer to the plants or fish tanks than HID lights – which is a huge advantage in effective light delivery. How long do the tubes last? The manufacturers are claiming an effective life of 15,000 hours with less than a 20% loss of output over that period. This is a far longer lifespan claim than most other lamps and needs to be treated with some caution. Replacement tubes are pretty inexpensive and it is suggested that 18 months is a more realistic time between changeovers.