May I please inquire the total cost of parts to build this cree light setup and the apx. build time? Awesome thread man!Last day of first vegging week . (That would be the seventh day ...)
Specimens: 2x Regular AutoFlowering of Unknown exact strain.
Pots: 20 liter
Medium: Black Peat-Perlite.
Ferts: Food Grade Mineral Salts .
Solid State Light Engine : 4x Cree CXA3070 3000°K 80CRI .
Drivers: 4x MeanWell HLP 80H-42 .
Driving Range : min 350mA - max 2100mA .Manually adjustable + manual OFF.
Cooling: ACTIVE (HSF ) .4x 120mm Fans 5.4 W nom. (each) .
12 speeds, manually adjustable.
Grow Space: SilverBox Evolution Grow Tent . 1.6 m x 1 m x 1 m
CXA's were driven at 350mA for six first days ,from today set at 500mA .
18/6 time scheme. ( 9.7 mols/dia )
Ta= 31°CView attachment 3204232
Tc of individual COB chips :
View attachment 3204233
The two youngsters underneath ...
View attachment 3204235
View attachment 3204237
Estimated Data:
View attachment 3204331
Cheers.
Total cost of Parts : Around 500-600 USD .May I please inquire the total cost of parts to build this cree light setup and the apx. build time? Awesome thread man!
That's really interesting sds. Doesn't that conflict with the PDF you listed a while back stating higher irradiances increased thc levels.The Effect of Electrical Lighting Power and Irradiance on Indoor-Grown Cannabis Potency and Yield
Abstract:
The floral development and potencies [Δ9-tetrahydrocannabinol (THC) contents] of cannabis plants were compared when grown indoors under high-pressure sodium lamps consuming electrical power at three densities (270, 400, and 600 W/m2). After a 3-week vegetative phase, plants were grown for 8 weeks, with lamps maintaining an artificial day length of 12 h. Foliar and floral yields were measured. Gas chromatography was used to measure the content of the psychoactive cannabinoid THC. Mean yields per unit of electrical power in each lighting regime ranged from 0.9 to 1.6 g/W, the highest being achieved in the lowest irradiance regime. The individual potencies of the separated leaf and flower materials were not affected by increasing irradiance. However, there was a corresponding increase in the overall potency of the aerial plant tissue. This was because of the plants in brighter conditions producing a higher proportion of floral material.
So ...At 270 W ( HPS ) x 1.6 gpw => 432 g
and at 600W ( HPS ) x 0.9 gpw => 540 g
Sure another reason to use more pieces of CXAs ,but driven as low as possible ...
But ....also ....
That's really interesting sds. Doesn't that conflict with the PDF you listed a while back stating higher irradiances increased thc levels.
I'm at 50w a sq/ft right now but I'm definitely dropping that down to 40w or less in the future. 50w is stressing them more than I like.
Have a feeling my 400w light could light up a much larger area than my 4' x 2' tent. Maybe a 4' x 4' albeit with less than optimal light spread akin to hps point source
Well ,that's one 'side' I never take into account ,432g using 0.270kW * 12 hours * 56 days * $0.33/kWh = $59.88
540g using 0.6kW * 12 * 56 * 0.33 = $133.06
That's 3.85 additional ounces of white LED homegrown for $73.18. A bargain in my parts! Of course, $0.33 is the top usage tier in an expensive market. In most cases the difference will be more like half, $40.
If you sell, the bag appeal of greater nug size and hardness from high intensity more than makes up for the electricity by itself.
)Photosynthetic response of Cannabis sativa L. to variations in photosynthetic photon flux densities, temperature and CO2 conditions.
Abstract
Effect of different photosynthetic photon flux densities (0, 500, 1000, 1500 and 2000 μmol m(-2)s(-1)), temperatures (20, 25, 30, 35 and 40 °C) and CO2 concentrations (250, 350, 450, 550, 650 and 750 μmol mol(-1)) on gas and water vapour exchange characteristics of Cannabis sativa L. were studied to determine the suitable and efficient environmental conditions for its indoor mass cultivation for pharmaceutical uses. The rate of photosynthesis (PN) and water use efficiency (WUE) of Cannabis sativa increased with photosynthetic photon flux densities (PPFD) at the lower temperatures (20-25 °C). At 30 °C, PN and WUE increased only up to 1500 μmol m(-2)s(-1) PPFD and decreased at higher light levels. The maximum rate of photosynthesis (PN max) was observed at 30 °C and under 1500 μmol m(-2)s(-1) PPFD. The rate of transpiration (E) responded positively to increased PPFD and temperature up to the highest levels tested (2000 μmol m(-2)s(-1) and 40 °C). Similar to E, leaf stomatal conductance (gs) also increased with PPFD irrespective of temperature. However, gs increased with temperature up to 30 °C only. Temperature above 30 °C had an adverse effect on gs in this species. Overall, high temperature and high PPFD showed an adverse effect on PN and WUE. A continuous decrease in intercellular CO2 concentration (Ci) and therefore, in the ratio of intercellular CO2 to ambient CO2 concentration (Ci/Ca) was observed with the increase in temperature and PPFD. However, the decrease was less pronounced at light intensities above 1500 μmol m(-2)s(-1). In view of these results, temperature and light optima for photosynthesis was concluded to be at 25-30 °C and ∼1500 μmol m(-2)s(-1) respectively. Furthermore, plants were also exposed to different concentrations of CO2 (250, 350, 450, 550, 650 and 750 μmol mol(-1)) under optimum PPFD and temperature conditions to assess their photosynthetic response. Rate of photosynthesis, WUE and Ci decreased by 50 %, 53 % and 10 % respectively, and Ci/Ca, E and gs increased by 25 %, 7 % and 3 % respectively when measurements were made at 250 μmol mol-1 as compared to ambient CO2 (350 μmol mol(-1)) level. Elevated CO2 concentration (750 μmol mol(-1)) suppressed E and gs ∼ 29% and 42% respectively, and stimulated PN, WUE and Ci by 50 %, 111 % and 115 % respectively as compared to ambient CO2 concentration. The study reveals that this species can be efficiently cultivated in the range of 25 to 30 °C and ∼1500 μmol m(-2)s(-1) PPFD. Furthermore, higher PN, WUE and nearly constant Ci/Ca ratio under elevated CO2 concentrations in C. sativa, reflects its potential for better survival, growth and productivity in drier and CO2 rich environment.