Lighting can be especially challenging to choose because of its technical complexity and relatively high cost. New growers tend to focus only on the overall Lumen output. Their thinking goes ‘brighter is better’, but that’s not always the case.
Let’s take a closer look at all the terms we need to understand about hydro lighting.
First of all, we come to Lumens: the term for brightness. Remember, Lumens is a unit for how bright a light is to human eyes. Strictly speaking, it’s not relevant to plants, but it does give us an idea of what to expect in terms of absolute brightness.
Far more important to cultivators is the PAR, or Photosynthetically Active Radiation. This is a measure of the light wavelength that plants can actually use for photosynthesis.
Every plant has their own preferences, but a PAR wavelength of 400-700nm is generally best for plant growth and flowering.
Once we have the correct wavelength, the next question is of intensity. How bright, from a plant’s point of view, should the light be?
For this purpose, we measure a light’s PPF, or Photosynthetic Photon Flux. The PPF is a measure of the amount of PAR a given light can radiate. The higher the PPF value per Watt, the more efficient the light source is for plant growth and optimum yield.
These measurements cover the factors we need to consider for the plants.
The next set of factors relate to the lighting device itself. Such as PPF Efficacy, which is a measure of light intensity vs power consumption. Basically, it expresses how much plant-usable light a fixture produces for every Watt consumed.
The PPF Efficacy is different from EFFICIENCY, however. Efficiency simply tells us how efficiently the ballast operates and how much power loss we can expect during normal operation.
These are the basics that need to be considered when deciding on which lights to purchase. Always do your homework and thoroughly examine the specs of the lights you are considering in relation to the crops you want to cultivate. Lighting can be an expensive investment, but doing your research beforehand can save you loads of time and money in the future. Happy hunting!