Quote Originally Posted by Rusty Trichome
Gee. I thought it depended on the bulb. Some are full spectrum, some are for street lights or security lights, some are for growing indoors, some for aquariums... Most have so many friggin lumens, doubtful spectral bleeding is a problem worth a mention. Especially if results verify it's worthiness.

Perhaps you should get to the point. Explain why we should be as concerned as you seem to be...? I grow killer buds with my 1000w HPS, and have found no lighting system for indoor growing that even comes close to the performance of an HPS system. I'd love to see an example of this 'photodamage' you refered to. I'd also like you to look-up the degredation process of CBD to CBN, and it's effects on the psychoactive properties of the THC. Personally, I use the UV light to enhance this degredation further and quicker.

But I'm curious...what do you propose as a "better" choice?
I see you are easily inspired to bicker and difficulty inspired to discuss....

First, most street lights are actually LPS, not HPS. Second, I'm fairly certain all HPS spectral content is so similar that it is not worth distinguishing them. Any so-called HPS with a drastically different spectral content is actually high-pressure-something-else and/or metal halide.

I said nothing about being concerned. I am simply presenting new evidence for the this-light-vs.-that-light argument. in the hope of some intellectual conversation. Regarding that: I can agree that the quantity (or however you want to call it) of light is more important than the quality. Therefore I can agree that 1000W of HPS is far superior to 90W of LED. But still, it can't hurt to try to improve the quality of light. As you put it, referring to CBD, the quality of light can improve the end product.

In all plants photodamage occurs which primarily destroys a major part of photosystem II. This destruction inhibits photosynthesis, or slows it down. As everyone knows, it is via photosynthesis that the plant grows at all. So, paradoxically, light makes a plant grow slower but without light it will not grow at all. As we can see above, some wavelengths cause more damage than others. Most of this damage occurs in the UV wavelengths but there is also a peak just shy of 600 nm. This means that the damage to the photosystem is most severe at these wavelengths. There is a process to repair the damage but that process draws from the same energy pool which could be used for growth and then, as you asked, there is the point:

The highest quality light source shouldn't destroy any part of the plant which causes it to grow.