Reflectors: what they are and how to use them
Are you thinking about a reflector and looking for the most suitable solution at the best price? What criteria should you use and which parameters should you consider? Then you are in the right place.
The basic parameters of reflectors that should be considered when choosing are the reflector's reflectivity, the light dispersion and its uniformity, the illuminated area and the recommended power for the reflector.
Reflectivity of the reflector is given in % and indicates how much of the incident light is reflected back onto the growing area. Reflectivity itself is very important because the lamp emits half of its output upward, away from the plant leaves, and the reflector redirects this light back where it is needed. Every lost percent therefore counts and the difference between a basic and the best reflector can mean up to 10% lost light output, which can cause lower yield or higher consumption due to the need to use a stronger light source.
The cheapest reflectors have values around 80%. Typical examples are reflectors costing a few hundred such as Hammer, in the lower mid-range reflectivity reaches around 90%, represented for example by Waveflector reflectors. The upper mid-range is represented, for example, by the WAVEflector Vegagreen series, which have reflectivity around 95%.
The highest class is represented by reflectors from the Adjust-a-Wings brand and its derivatives, which in the top series have reflectivity over 97% and all series also have the most even dispersion of reflected light.
This brings us to the second parameter, which is light dispersion. Making use of all the light produced by your source (usually a lamp or a CFL fluorescent lamp) does not by itself ensure even plant growth and its maximum utilization. Each reflector reflects different intensities of light to different areas, so some plants receive more light while others receive less. Differences can be as much as 50% and, considering that a reflector redirects about 50% of a lamp's output, the difference can be very significant and negatively affect the plant. One will have too much light and may begin to wither — information on lowering the temperature in the tent; conversely another has too little light and its full potential is not utilized.
Quality reflectors are also made in several sizes and it is necessary to choose one that best matches your growing spaces, and likewise we do not recommend using light sources with higher power than recommended for the reflector. Unless you have a specific reason, you will probably not achieve higher yields, rather the opposite.
A specific type are CoolTube reflectors, where the lamps are enclosed in a glass tube and allow outside air to flow around the lamp directly out, thereby minimally affecting the temperature in the grow tent. Due to the need to exchange air for plants as well, this solution is particularly suitable where the grower is dealing with problems of excessively high temperature in the tent and standard ventilation is no longer sufficient.