joesoap2013
Well-Known Member
That one is 45
2x4 tent , light upgrade.
- Thread starter Moistvonlipwig
- Start date
That one is 45
pegboy
Well-Known Member
Good point!! I've done 2 grows with mine so far and not sure if I've had it over 60% yet.
joesoap2013
Well-Known Member
Look at the drop off it the light spread on the spiderfarmer 
It's cause it's 14 inch's wide
The middle has to be really high to bring outside its footprint up to decent levels
It's cause it's 14 inch's wide
The middle has to be really high to bring outside its footprint up to decent levels
60% is about 900µmol at 10" which is good light but the icing on the cake is that you can raise that light about 8" or so, which will let your temps fall, and still get "lotsa light" on the canopy.
I've done half a dozen grow with the Growcraft and have had temps at 80-85. It was only this year that Westmoreland got sponsordhip for a wide audience about keeping temps way down in flower.
He did a YT video four years ago. It's interesting to watch because you can see he's a college "kid" who gets to do neat shit with cannabis. I watched it but he was talking about "hemp" so I didn't pay much heed.
My notes from that video are below. Check out the last paragraph. Yup, when opportunity knocked, I was out back, taking out the trash.
"
Mitch Westmoreland
Discusses temperature - Optimum temp to maximize CBD and yield and keep THC below 3%
Plants grown at 73 and 84 degrees. Plants at 84 were taller but colas were smaller in girth.
At 84 little but taller, a bit more vegetative biomass. Yield wasn't all that affected by the increase tempearature. At 84°, cannabanoids were roughly 1/2 of what they were at cooler temperatures.
Suggest that the optimum is between 70 and 80.
Fertilizer
You've probably come across hundreds of companies promising to boost yield. They "lack a theoretical basis" and you'll probably end up just throwing away money and excess nutrients that will end up polluting our nice rivers.
We recomend that you fertilize it just as you would tomatoes. This is a good comparison there's nothing particularly special about hemp.
One of the big claims that you'll see coming out out of the cannabis industry is that high phosphorus will increase yield and will increase cannabanoid content. We've tested this.
We look at a range of phosporus treatments ranging from borderline deficient to excessive. We found no significan difference, especially as we move toward the rates recommended by the cannabis industry. This has implications because phosporhus is a potent pollutant in our environment.
What we're trying to do is get growers to use as little P as we can while still getting a good crop.
Drought stress
In veg - they're very resiliant. Got to the point where they were severely wilted. They recovered so that it seems as if nothing happened. Hard to see which one's were stressed and while ones were well watered.
In flower - yellowing and dropping of leaves and reduction in yield. CBD and THC does not make production increase.
Temperature - yield increased slightly. CBD and THC plummeted - "cut in half basically". We don't have a good explanation for this right now. We're going to ssee if we can reproduce this and see if we can come up with an explanation for what's going on."
I finished testing a Mars SP3000R today which is, essentially, an LED clone of HPS but it the PPFD map is not suited to tent growing. Plus, it puts out a lot of heat so I'll be returning it. After a few days of research and analysis, and then testing the Mars light, I'm back to using my Growcraft. It's got more red in the spectrum than the 4500 but the PPFD map isn't as good. Somehow, I'll get by.
With that 4500 you've got, however, you'll be able to follow his advice to a T, so you've got a very rare light that will let you produce harvests that will be both high yield and high quality. Congrats.
I don't own the light but I've spent a few hours studying the G4500 and the SE4500, both the current version and the previous version.
The previous version was an excellent light with a 430 watt driver that put out the highest PPFD I've seen (with the exception of the Growcraft Ultra) with the best PPFD map on the market. For whatever reasons (and I suggested a few in a previous posting) Spider put out a new version of those lights with only a 320 watt driver. The result that they're producing "just another light" instead of "holy shit, that's a lot of light" light.
A second change was to standardize on one spectrum. The original G4500 had more blue in the spectrum and was more powerful than the SE 4500, by about 100µmol. The current lights still use Osram in the G and Samsung in the SE model but, by visual inspection of their marketing material, both lights have the same spectrum and that spectrum has less blue and more red. I prefer the new spectrum but would rather have had the PPFD if the G model.
That was then, this is now. The Spider 4500's have very good light output, excellent uniformity, and a very good spectrum. If I was in the market for a 2' x 4' light fixture, I'd go with the G4500.
pegboy
Well-Known Member
Very intersting!!60% is about 900µmol at 10" which is good light but the icing on the cake is that you can raise that light about 8" or so, which will let your temps fall, and still get "lotsa light" on the canopy.
I've done half a dozen grow with the Growcraft and have had temps at 80-85. It was only this year that Westmoreland got sponsordhip for a wide audience about keeping temps way down in flower.
He did a YT video four years ago. It's interesting to watch because you can see he's a college "kid" who gets to do neat shit with cannabis. I watched it but he was talking about "hemp" so I didn't pay much heed.
My notes from that video are below. Check out the last paragraph. Yup, when opportunity knocked, I was out back, taking out the trash.
"Does Hemp Need Extra Water and Fertilizer?
Mitch Westmoreland
Discusses temperature - Optimum temp to maximize CBD and yield and keep THC below 3%
Plants grown at 73 and 84 degrees. Plants at 84 were taller but colas were smaller in girth.
At 84 little but taller, a bit more vegetative biomass. Yield wasn't all that affected by the increase tempearature. At 84°, cannabanoids were roughly 1/2 of what they were at cooler temperatures.
Suggest that the optimum is between 70 and 80.
Fertilizer
You've probably come across hundreds of companies promising to boost yield. They "lack a theoretical basis" and you'll probably end up just throwing away money and excess nutrients that will end up polluting our nice rivers.
We recomend that you fertilize it just as you would tomatoes. This is a good comparison there's nothing particularly special about hemp.
One of the big claims that you'll see coming out out of the cannabis industry is that high phosphorus will increase yield and will increase cannabanoid content. We've tested this.
We look at a range of phosporus treatments ranging from borderline deficient to excessive. We found no significan difference, especially as we move toward the rates recommended by the cannabis industry. This has implications because phosporhus is a potent pollutant in our environment.
What we're trying to do is get growers to use as little P as we can while still getting a good crop.
Drought stress
In veg - they're very resiliant. Got to the point where they were severely wilted. They recovered so that it seems as if nothing happened. Hard to see which one's were stressed and while ones were well watered.
In flower - yellowing and dropping of leaves and reduction in yield. CBD and THC does not make production increase.
Temperature - yield increased slightly. CBD and THC plummeted - "cut in half basically". We don't have a good explanation for this right now. We're going to ssee if we can reproduce this and see if we can come up with an explanation for what's going on."
I finished testing a Mars SP3000R today which is, essentially, an LED clone of HPS but it the PPFD map is not suited to tent growing. Plus, it puts out a lot of heat so I'll be returning it. After a few days of research and analysis, and then testing the Mars light, I'm back to using my Growcraft. It's got more red in the spectrum than the 4500 but the PPFD map isn't as good. Somehow, I'll get by.
With that 4500 you've got, however, you'll be able to follow his advice to a T, so you've got a very rare light that will let you produce harvests that will be both high yield and high quality. Congrats.