GH RainForest 6 plants 400W LED Test

Hey all overgrowers!

Finally I’ve compiled all my photos from last grow. This was actually a test of custom tailor-made grow LED light. RainForest from General Hydroponics as grow method was failproof at the time and chosen as proven platform. This time with 6 Hash Plant (clones but originally selected mother from Sensi Seeds pack at early 00’s).

You can see same grow cabinet footprint with different combinations here:

So you can easily compare results with Osram Plantastar 600W High Pressure Sodium (HPS) to this custom 340W LED light.

This light had 3 regimes - each powering different circuit of diodes in different field

  • Grow - 156W in blue Cree diodes
  • Bloom - 177W in red Cree diodes
  • Extra UV - 8W in ultra-violet spectrum

For vegetation period of small clones just grow part was used saving electricity costs. Once plants got bigger also red spectrum was switched on totaling 340 watts. For second half of blooming period, UV extra spectrum was turned on…

This lamp had this extra ultra-violet spectrum because it was a prototype test light.

I’m not sure if those 8 watts of ultra-violet light has done something beneficial to the plants, but I can tell you for sure that it was functioning as you could feel sick after spending few minutes nurturing plants with it on… After feeling sickness I decided to turn UV off every time before entering the room. UV is not healthy thing for living animals and definitely not healthy for human skin and eyes.

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LED lamp with passive cooling. There were not any temps problems so I didn’t bother to create air channel above the cooler… Man this thing is heavy! About 15 kilograms! We fixed it properly to the ceiling…

Vent is 125mm ~ 350 m3/hour

From photos you can see that plants didn’t vegetate so wildly as in previous grows. Week-to-week changes were really small.

29/3 (10 days of vegetating)

5/4 (17 days of vegetation)

5/4 (17 days of vegetation)

Growth in detail

After about one month of vegetating (reeaalllly long time) it was decided to switch to 12/12 and screen of green net was placed as usual. But plants haven’t reached the net in reasonable time.

Switched 17/4

Photo from 22/4 (5 days of flowering)

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Man, this was really painfull grow! This weren’t good news for us neither the lamp assembler. You can see that vigorosity has basically dissapeared compared to previous old school HPS grow. We were really badly surprised.

21/5 - one month of 12/12

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Mixture of spectrum creates strange “sharpness”, this photo is taken with LED on…

28/5 - after six weeks flowering (42 days)

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THC glands were nice for fifth week, but it missed the size, volume and weight.
Buds were ripe at 42 days and this last photo is just before harvesting it…

Detail taken 29/5 (final day)

For near future I’m done with LED lights and will wait for next generations of LED chips… Maybe it was matter of bad selection of spectrums, anyway It didn’t work as planned … it hardly worked at all… 2,5 months lost with this experiment. But sometimes you just have to take a sacrifice for the sake of science I guess :)…

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Just for the reference I’ve dug old tech sheet to be clear and accurate about spectrum and light output… I wanted to add technical specifications of LED lamp used. (so I know what to avoid next time :slight_smile: )

From the tech sheet:

LEDgrow EVO I

The light source based on LED technology destined for artificial cultivation of plants

Advantages of new lighting fixtures than any other product on the market:

  1. Reduced power consumption (given low-power diodes)
  1. longer life = 80.000 to 100.000 hours (About 3 times longer than the discharge lamp 5 - 8 times longer than the fluorescent lamp)
  • Maximum life quality is achieved by cooling (Cooling element / device is installed, part of the luminaire)
  1. cold light source
  • less need for ventilation
  • Lets you get closer to the light source to the plant
  1. high efficiency up to 100 lm / W (fluorescent lamps 60 to 80 lm / W)

Phase switch the light spectrum to grow / Flower

  • Optimal for the complete development of the plant in two phases
    - There is no need to purchase multiple light sources (growth / bloom)
    - Need not be combined with other lights

High luminous flux

  • In the growth phase of about 14,500 lm
    - In the flowering phase of approximately 20,000 lm

Optimally preset value of the light spectrum

  • Growth phase 4400 - 6700 K (ie. The blue spectrum)
    - In the flowering phase around 2700 K (ie. Red spectrum)

Operating costs for energy consumption according to the phases

  • In the growth phase input power 150 W
    - In the flowering phase power about 270 W
    - Average power throughout the = 200 - 220 W / 20,500 lm (100 lm / W)

Built weak sources of UV radiation, used during flowering and ripening phase

  • Fall simulation of natural sunlight
    - Increases immunity and resistance of plants and the quality of the outcome of the harvest
    When using high-quality reflective material (more than 90%), e.g. special film can be used LEDgrow lamp to illuminate the area to one square meter.

Overview of CREE chips:

type LED number color spectrum Colour temperature efficiency luminosity power
P2 - 3W 59 pcs red 2700 °K 67 lm / W 11,859 lm 177 W (Warm white) (660 nm)
Q5 - 3W 24 pcs blue 7000 °K 107 lm / W 7704 lm 72 W (Cool white) (470 nm)
P4 - 3W 28 pcs neutral white 3700 °K 80 lm / W 6720 lm 84 W (600-610 nm)
UV - 1W 8 pcs ultraviolet 10,000 °K 45 lm / W 360 lm 8 W

Total: 119 pcs growth and flower average efficiency: of about 78 lm / W 26,643 lm 341 W

Spacing between diods: 3 cm
Grid dimensions: 54 cm x 24 cm

lookin good. thats a sick light. did you build it yourself?

It was custom built by local start-up company. Probably first of their lights for growing purposes. Old generation of Cree chips. I was given this lamp for the test (because I could compare pics to other 600W HPS grow