The quick answer to how high should a grow light be is not very high at all. Actually, we want the grow light system to be within a foot or two of the canopy. Does that sound too extreme for our grow equipment? It is actually the best way to go to maximize our indoor grow light. And, as we can see with the ppfd chart, it can only happen by using Light Rail light movers. This is also the easiest way to see the answer to the question of do grow light movers work?
The ppfd chart tells the story
With that ppfd chart, take a look at the grow light system ppfd readouts at 15 inches. This was for a standard double ended grow light at 1,000 watts. Compare the grow light system readout of the LightRail light mover on the top of the graph. That’s in comparison with the stationary grow light system readout on the bottom. So, for how high should a grow light be, the LightRail light mover gives an even grow light output which will result in an even plant canopy. The stationary double ended grow light would produce too intense of an indoor plant light to the plant canopy. So, it’s easy to see the difference. And, then it’s easy to understand the cause and effect of moving our indoor grow lights. And, this works for all grow lights and grow light intensity as we can see in this link covering all the grow light numbers.
The exception to the rule
For how high should a grow light be above seedlings compared to how high should a grow light be above plants; that detail will change our grow room design. Grow light interaction with seedlings needs to be minimal. Typically a fluorescent grow light is the best match with seedlings, and a small scale one at that. We would never want to put very young plants right under a powerful grow light. That’s whether it is a moving grow light or not.
Young plants need to start out with a less powerful fluorescent grow light. Then, they can work their way towards a stronger indoor grow light. That stronger grow light can then be a 1,000 watt double ended grow light or a metal halide grow light. Or, that indoor grow light can be an LED grow light or a plasma grow light. So, young plants need the grow light system to have some distance to the plant canopy. In no time, however, they can be positioned under a more powerful grow light. And, that’s as a moving grow light along the light mover rail.
Stationary grow lights are at half strength
Grow light companies will have their own recommendations for how high should a grow light be. Of course, that is in stationary grow light terms every single time. Because their own recommendations are looking at the least effective setup for output and yield effect, they must be ignored. Their grow room setups would require end to end grow lights, each working inefficiently. And, each of these stationary grow lights would be performing at about half strength. Again, compare the ppfd chart, LightRail light movers versus stationary grow lights. Those numbers tell us what we need to know.
Better grow light, angled grow light and ideal Leaf Area Index
The ppfd chart numbers also tell us why we get faster growth and significant yield increases with LightRail grow light movers. We can easily visualize the even plant canopy. But, we can also visualize the angled indoor plant light reaching more of the leaves. That means more of the leaves are working for the good of the plant. And, each of those surfaces receives the indoor plant light at just the correct period of time which is an example of Leaf Area Index. These grow light system details are important. So, for that general question we hear of what is the best grow lamp to use; it would be the grow lamp that is moving on a LightRail light mover.
How high should a grow light be?
We can throw away any preconceived ideas of how high should a grow light be when we have our grow light system moving on LightRail light movers. And, that’s for the grow room setup, the grow tent setup and for greenhouse lighting. Whether we use the LightRail 3.5 Kit, the LightRail 4.0 Kit or the Extreme Duty Greenhouse Package, we will see the following change. We can then be bold with our indoor plant lights. And, we can fire in our grow lights to get maximum ppfd right to the canopy. That gives us maximum grow light performance. And, we can only get this with LightRail.