KJ6EAD--Thanks! That might work, except it needs more nm.
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Just a quick technical note.
nm are a unit of distance. 1,000,000,000 nm = 1m.
In this case nm are used to specify the colour of the light by specifying the wavelength of the light emitted. "More nm" (more strictly a longer wavelength) means a lower frequency, i.e. toward red.
The wavelength in nm gets smaller as you go from infra-red to red, to orange, to yellow, to green, to blue, indigo, violet, and then ultra-violet. (And the spectrum goes far further in both directions -- it's just this part is what's called visible light.
So, properly, you would say "The wavelength is too short", "The light is too orange", etc.
Incidentally, the eye is quite insensitive to red, and most "red" warning lights tend to be at the orange end of red. For your application the optimum may be a deep red, or even extending into near-infra-red. (I haven't checked the wavelength to be sure)
One of the issues of having a highly intense light source is eye damage. LEDs tend to be an almost point light source, so the bright point of light can be dangerously bright. IPL and other intense light sources used for cosmetic and medical purposes are applied while the person undergoing the treatment wears protective eye covering. Beyond that again you have laser treatmnts that are actually designed to burn the skin. Whilst it is unlikely that the intensity from your source will approach even the lowest of these levels, the bright points of light certainly exceed the average brightness of the light source. I would not recommend staring at these light sources (especially higher powered ones) for any length of time.
Having said that, an array of 3W red LEDs would probably be better, with each of these putting out up to 1/2W of light. 4 of these would give you about 2W of light in a much smaller footprint. However you would have some issues in driving them.
For practical purposes, I would use the grow-light as it currently is, and see if you notice any effect. Due to the lower incident intensity, it is likely to be far safer than a higher powered alternative.