Light %

Delps8 said:

The stage of a cannabis plant is a handy guide but that's all. Cannabis is a light whore loves light. Give you plant as much light as it can handle and it will grow incredibly well.

The XS-1500 Pro will put out quite a bit of light and, at 16" hang height, you're at about 600µmol. I use word "about" because I don't have a PPFD map for that height so I'm looking at the one on the Amazon listing and the info here. 600 is considered the minimum amount of light that you should give a plant in flower. Why? Because.

That's the number that I think Bugbee provides and I know that DeBacco (You Tube) states that but DeBacco isn't a researcher. He repackages a lot of what Bugbee says but I haven't read anything of his that's not in synch with Bugbee and others.

An excellent source for this is from Bugbee student, Mitch Westmoreland, who published a couple of YT videos this Spring with some of the research that he did for his PhD. Every grower should watch at least one of his two videos. He lays out his research very well and it's pretty simple 0 give you plants at much light as they can tolerate with ambient temps up to the mid-80's. Do that through veg and into about the second week of flower. That will allow the plant to build out its infrastructure. Once you're in about week two of flower, if you want to maximize secondary metabolites, keep the temperature at the top of the flowers <=78°F.

OK, great info but it doesn't answer your question, because it depends on the grow. If you grow is "firing on all cylinders", you might be able to go to 100% and drop your hang height to 12". Per cocoforcannabis, that's going to get 950µmol± on your plant. That's quite a bit light but cannabis will handle more than that in ambient CO2.

On the other hand, you might drop the light to 14" and get canoeing of your leaves. If that's the case, you should check your grow and see what's not set up right. VPD could be off or not enough//too much wind in the tent or nutrient level too high. It could be a variety of things that, if they get adjusted, can allow you to feed your plants better.

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desplegado said:

Is ppfd next to the names and the lux it is or somewhat the top like the 10,000?

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desplegado said:

But what I mean is when to I turn up the light% or woukd I even have to right now its at 50%

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desplegado said:

Is ppfd next to the names and the lux it is or somewhat the top like the 10,000?

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desplegado said:

U mean 100% at 16 in? There just starting to grow there pistils

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Delps8 said:

That's not generating much light.

"have to" - there's no "have to". It's completely up to you. Cannabis will thrive at very high light levels but it will also grow well at modest light levels.

If your hang height is 16", a well setup grow will use 100% but the only thing I know about your grow is that you're giving it 50% of a Vipar at 16" so it might not be the case for your plants.

If I assume that your grow is in decent shape, I would advise you to turn up the dimmer dial from 50% to 70% and then watch your plants. If they can't tolerate that change, turn the dimmer back down and figure out why they can't tolerate that amount of light.

I sense some timidity/lots of caution. Fair enough. If there's too much light, the plants will tell you in a few minutes. They'll curl the edges of the leaves or take other action to get away from the light stream. No big deal. Just turn it down a bit.

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larrypizzimp93 said:

If it’s 150 watts just understand the buds are gonna be small and not as dense. Especially if you have a plant with bad genetics. But I would keep it around 12 inches from top and if the top is yellowing, raise light (that’s light bleaching)

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