So I had some questions about light spectrums. I picked up a viparspectra P600. I have been seeing stuff about changing light from one growth stage to another. Blue spectrum vs red spectrum etc etc. The grow light I have has a dimmer knob, but nothing to change the color of the lights. There are some different colored LED’s on it, however. Should I be dimming the dimmer knob to achieve those lights? Is that how that works on cannabis? How would I know which percentage of light shown by the knob (it goes from 15% all the way to 100%) corresponds to which part of the light spectrum?
Intensity changes for stage of growth. Start low on veg and increase til plant can’t handle anymore and canoe while going for flower
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Lights have come so far in the past 15-20 years scientists have been really busy causing us to have to buy new lights on the regular lol they were studying which spectrum to use for growing and found that blue was better for veg and red for flowers so that was the thing for some time but then they figured out that yes the different colors were better for the different stages but that it was even better for growth to mix the colors because each color had benefits during all stages so we all bought full spectrum but it wasn’t actually full spectrum it was still just red and blue then the bastards said that plants benefited from yellows whites and so now we’ve all bought the new full spectrum lol next year we’ll have to change again I’m sure hope this made a little bit of sense lol I tried anyways 
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A simple way to put it -
Blue spectrum less stretch more leaves,
Red spectrum big buds.
I’d stick with your full spectrum lights until you get everything else right, then start supplementing different lights.
Start dim & work your way up a little per week. 
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Some blurple lights will have a veg switch and bloom switch. It’s kinda gimmicky if you ask me. Most lights are full spectrum, what differs is how much blue or how much red they have in their light spectrum. Viparspectra is usually heavy in blue spectrum. That’s why I use mine for vegging. Here is your lights spectrum. It has everything the plants need but could use more deep red for flowering.
Here is the spectrum for the rspec quantum boards that are built for full grows.
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God dang nerds
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The only time that I used only one switch (veg) was for my seedlings I liked that it lowered the watts so I could keep the light lower but only ran it that way for about 10 days or so
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I have a couple viparspectra 300’s for veg. I just run my seedlings under those at about 36”
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It is funny. I was just looking at that spectrum graph this morning and comparing it to some of the budget led spectrums. This their 130 full spec series 3.
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See that graph is weird. Turning on the bloom switch doesn’t turn off some of the blues. It just turns on more reds. Unless they’re separate graphs for veg only and bloom only.
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I believe the latter. It says the board switchable. (Veg or Flower - UVA on/off
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There’s the other issue with those type of lights. If you just run one switch you’re cutting light output. They claim 1000w which translates to 200 true watts with both switches on and about 100w with a single switch.
That’d be cool if HLG could combine a bspec and rspec and allow for switching. If you had a 260 it would be 260 watts with bspec on and 260w when you switch to rspec and turn off bspec.
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There are multiple reasons why you don’t and probably won’t see that. . There is difference in fv, and measured light intensity from blue and red leds at same current are different. So even if driver setup was identical, the final power would be different. Someone could probably crunch numbers and calculate difference, but nobody has because Veg time is 33% longer so same dli is achieved with 33% less power.
Chilled tech use to sell 3 channel boards with white, red, and blue/uv capable of being controls separately. I think cutter still does, so they have definitely dabbled in making each independently controlled. But nothing about keeping power levels the same.
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Interesting, didn’t know they ran at different intensity at different current. But still if the blues and reds aren’t running at the same time you just need to adjust the current when you switch between the two. I’m always adjusting my current throughout the plants life anyway.
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Is slightly more complicated than what I typed. I always seem to land on side or the other, ha!
If you grab blue and red from same line, like cree xpe-2 for example. The fv on blue would be something like 3v at test current, but the red wi be more like 2v. One led not that big of difference. But if you throw 20 of each on a pcb then run 4 pcb’s, a current of 1000ma could be something like 80 watts difference running blues vs reds. Would make something like 260 watts running blues vs 260 watts running reds difficult. Not impossible though. Then you also have the difference in photon output as well. Even if you matched power so 1 watt of blue vs 1 watt of red, they won’t measure 1.0 vs 1.0 on spectral distribution chart either. That could be figured out as well, but would likely look a lot different than having identical power in each.
If you are simply looking at dimming from a blue dominant spectrum to a red dominant spectrum and having similar power in each is a piece of cake though, and not terribly expensive. Bridgelux has a strip (vesta line i think) that has 2700k 90cri on one channel and 5000k 90cri on a separate channel. If you wired each channel to its own identical driver, would give you ability to dim or increase either, both, or neither. You could essentially get to any final cct between the 2700k and 5000k mark. But that is also different than just bringing in blues or reds too.
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Luckily I have a separate veg and flower space. But if I went back to a single space I’d definitely want to go that route instead of swapping boards every time I switched to flower.
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You are more ambitious than me. I would certainly run dedicated lights for separate spaces, but there would be no module changes. I won’t even change fixtures.
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<----- veg. Flower-----> 2 to separate places man I cant stand being stuck in one space I will never do that to my self… if I got 16 sq feet 12 are gonna be for flower and 4 are gonna be for veg… I can run seed to harvest seed to harvest not practicle in my eyes…always wanted to get a propagation tent IF I ever needed to be confined to a tent
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