Marijuana Light Spectrum

Cru3l

Well-Known Member
Dont mean to hijack this thread, but I'm currently using a 600w HPS Digilux Bulb & Nexgen Digi Balast.

I'm considering swapping out my 600W with: 12 32-watt T8 5000K Full Spectrum Bulbs.

I bought the hood/ballast from Home Depot, then put in the T8 bulbs purchased from my local hydroponic store.

Any thought? I'm focused specifically on flowering.Here's some pics of the lights, and previous grows.
 

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Throwin

Member
Looks like I'm using the exact setup for flowering Cru3l. I'm not getting big buds or a great quantity of buds. The plants look great but are not producing a great quantity of bud compared to the size of the plants. So now I'm looking at upgrading to the Quantum Badboy T5 12 lamp. Hoping the boost in lumens will increase bud growth. How are yours growing with the 12 T8?
 

RalphCurtis

Member
I think most of the pot farmers have gone a bit past thinking of light in Kelvin scales. Withe the advent of LEDs true spectrum, in nanometers, is now whats happening. True, the warm white CFLs have more red in them than the cool whites making the former a better flowering light and the latter a better vegitative selection, but they both are hodgepodges that contain a lot of useless light. HPS is a rediculous choice given whats out there now.

I think the LED thing will get past the herasy stage and folks will see that making light that a plant can use..not making light it cannot as well as not making heat..the way to go. I use 720 watts of LEDs with a red bias for flowering in a 3 by 6 foot room and about 500 watts with a blue bias to veg. LED lights are OK ...Blackstar and the lot...but you can spike them with blue and red 3 watt high power leds and really rock. You can bias a flowering LED with coolwhite CFLs as well and cut your equipment costs.

Given the fine tuning you can do with LED light..you will put most of your electrical consumption into the plant.

There is little add on costs here. Heat..is largely gone as is its management and the HPS equivelent of 750 watts of LED is about 1500 watts or more. 1500 watts of HPS in a 3 by 6 foot grow tent would be an oven..
 

growlife1

Member
I think most of the pot farmers have gone a bit past thinking of light in Kelvin scales. Withe the advent of LEDs true spectrum, in nanometers, is now whats happening. True, the warm white CFLs have more red in them than the cool whites making the former a better flowering light and the latter a better vegitative selection, but they both are hodgepodges that contain a lot of useless light. HPS is a rediculous choice given whats out there now.

I think the LED thing will get past the herasy stage and folks will see that making light that a plant can use..not making light it cannot as well as not making heat..the way to go. I use 720 watts of LEDs with a red bias for flowering in a 3 by 6 foot room and about 500 watts with a blue bias to veg. LED lights are OK ...Blackstar and the lot...but you can spike them with blue and red 3 watt high power leds and really rock. You can bias a flowering LED with coolwhite CFLs as well and cut your equipment costs.

Given the fine tuning you can do with LED light..you will put most of your electrical consumption into the plant.

There is little add on costs here. Heat..is largely gone as is its management and the HPS equivelent of 750 watts of LED is about 1500 watts or more. 1500 watts of HPS in a 3 by 6 foot grow tent would be an oven..
Interesting and confirms what I have learned. I'm a newbie about to jump in and am ready for a setup like yours. When you say you "spike" with 3 watt high power leds do you mean UFOs that are all red or all blue?
 

cam1000

Member
Im trying some autos, my lights are a 600w hps two 4ft by 6 bulbs T5s. T5s work great for veg on some seeds a friend had move them to hps for budding got some shit but not much bud would t5s help with buding with my hps?
 

Mikey Trees

New Member
If this is the situation why is halogen so bad and we use hps i thought flower was 22700-3450 my bad thanks for the lesson can you elaborate more?
 

Dr. Who

Well-Known Member
If this is the situation why is halogen so bad and we use hps i thought flower was 22700-3450 my bad thanks for the lesson can you elaborate more?
The last guy's right.. This thread is now a zombie. You brought it back to life.

You have something to consider.

How do you beat the sun's spectrum?
The plant has evolved for millions of years eh?
So it's evolved to work best under what it gets outside.

THAT is what you want to go for..... Not just "what works"....
 

Mikey Trees

New Member
i have been doing countless research for an experiment a large scale small oxy moron experiment would one the doc or Blake be willing to help in regards to some ideas i am tinkering with Is there a way we could correspond privately?
 

I'mBatman

Well-Known Member
hiya daydrops

Forget 'brightness' it's not relevant.

The suns 'real' kelvin temperature is somewhere around 5,800 degrees kelvin, but because the sun is not a perfect 'black body' (the standard for calculating kelvin temperatures of light) its adjusted kelvin temperature is somewhere around 6,400 degrees kelvin.

6,400 degrees kelvin is predominantly 'bluish-white' light and this is the best kind of light and kelvin temperature for vegetative growth - primarily because in nature the time of year Cannabis is in vegetative growth is during the long hot days of summer where the suns daylength is the longest and receives the most 6,400k light. The reasons it changes for flowering is again because of the predominance of the kind of light found from the sun when Cannabis enters it's floral stage - usually at the start of Autumn or Fall when the days get shorter and the nights longer thus reducing down the daylength significantly. Sunrise and Sunset account for almost 50% of the suns light during the short days of Autumn/Fall and sunrise and sunset are made up of almost entirely red spectrum light due to the angle of the suns rays hitting the earths surface. Therefore as sunrise and sunset account for almost 50% of the sun total light output at that time of year it necessarily follows that 50% of that light will be entirely in the red end of the visible spectrum - hence the 2,700k colour temperature being favoured for flowering. In reality a mixture of red and blue light is required in flowering due to the other 50% of the spectrum being more blue in colour.
Thanks for the info. I gave up n just mixed my cfl's. I figured it couldn't hurt much.
 

Flowki

Well-Known Member
Is anything better than the power use/cost/simplicity to reward ratio of mixing or swapping out red/blue cmh lights?.

For example 1 600hps swapped out for a 315 ''blue'' and 315 ''red''. Would easily cover 4x4 (more effectively than the 600 3x2 imo) with a far better spectrum to reduce stretch and increase potency/reduce flower time. What's the avg cost to do that with cob?.
 
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