6400k would give me 452.77625 and 5500k would give me 526.866909091 which is better? what does it mean?
Light travels in waves. The wavelength determines the color of the light. The numbers you just calculated are the length of each wave. The first numbers(6400K, 5500K) are the correlated color temperature. Just different ways of measuring the color of the light. If you're using CFL's then you will be looking at the first numbers because that is what is listed on the bulb specifications. I believe the only lights that go by wavelength are LEDs.
ahh i get that! but now im confused about this: 5K - 7K Kelvin: Strong Blue Light. Promotes bushy growth. Ideal for rapid growth phase of plants. This greatly enhances all-around plant growth when used with super high output, (such as high pressure sodium or 3K warm metal halide lamps). 4.2K - 4200 Kelvin: Cool White Flourescents. Can be used as supplemental blue lighting when used with a 3K source. 4K - 4000 Kelvin: Neutral Metal Halide. Best single source for plant growth, producing shorter, bushier growth than 3700 Kelvin and color rendition. Used in general plant lighting. 3.7K - 3700 Kelvin: Softer Metal Halide(coated). This coated lamp is used in general plant lighting and for more rapid growth than 4000 Kelvin produces. 3K - 3200 Kelvin: Warm Metal Halide. Highest photosynthetically active radiation (PAR) value of all HID lighting for all phases of plant growth. PAR watts account for the nutritional value of light and are a direct measure of the light energy available for photosythesis. 2.7K - 2700 Kelvin: High Pressure Sodium Lamps. Redder color mix, used for propagation, blooming, supplemental greenhouse lighting. theyre saying 4k is ok for overall growth. does that mean i can buy 4k bulbs and use for veg and flower? this was out of a grow bible
What grow bible is that from? I've seen people using 4000K before, but everything I've seen indicates that it's not optimal for growing. Maybe someone with more experience will chime in.
OK I have read this thread several mores times every few days and now it's all starting to click but more importantly it is now sticking to my brain. Thanks to the OP and everyone else who has chimed in..appreciate it !
help out peoplee! http://forum.grasscity.com/lighting/1200096-help-lighting-2700k-over-random-bulb.html#post17690315
You're good to go. And if you're growing from seed have the lights about an inch above your girls when they pop and for a least 3 hours, 3 days is best. This will keep your plants shorter and with shorter internodal lengths. You will also end up with a broader canopy. A broader canopy=more energy for your plant.
seeking advice about lighting My seedlings are about 4 inches sprouted above the rock wool. The have their cotyledon leaves but are beginning to start their true leaves. when should i start placing my 75w 1300lumen 5000k cfl lights on them? right now they are in total darkness and seem to be enjoying it. Thanks
Hey I've done a couple of grows but am now taking things much more seriously, and have found this guide intensely useful. I do appreciate it, but there is just one sentence here "The shorter wavelength blue light penetrates water better and more quickly than red, which is slower and absorbed more quickly. " [SIZE=12.800000190734863px]That doesnt make great sense, is that last part simply meant to say "slower and absorbed more difficultly"[/SIZE] [SIZE=12.800000190734863px]Any help is greatly appreciated.[/SIZE] [SIZE=12.800000190734863px]Regards[/SIZE] [SIZE=12.800000190734863px]The Pharmacist [/SIZE]
" Blue is used at the same rate as red because it is more available for reasons mentioned above." Could someone simply explain why the rate is the same, and which light is absorbed quicker during moisture, "Blue or Red".
Great! very informative post about led lights I have read this I got it that how lights do the process of photosynthesis and it helps me in my studies as well. Thanks for sharing this.
I'v always abhorred growers using Watts as a unit of light measure. As a student in electricity, It's easy to say that Watts is a product of Voltage and Amperage. All of which are a factor of power W / A = V W / V = A 746w = 1 Horsepower the type of metal, the chemicals inside, all contribute to light output. Not necessarily the power used to supply it (although it is deffinitely a factor) comparing the wattage of LED vs CFL vs MH is like determining the quality of a cars paint job by the amount of horsepower it has.
I Hypocritically agree. I do find Lumens as if not more abhorrent and sadly have used both. It would be nice to use Photosynthetic Photo Flux Density or PPFD or better yet PAR per watt or PPFD per watt? I would also like to see that at different levels so i can know how much throw the light has. also if you could somehow have a BTU rating that would tell you how much additional energy it will take to run the light would be awesome.
i am extremely new to all things regarding growing, just doing some research and found this information. have to admit, it confused the hell out of me. I plan on using LED lights or CFL. So far my understanding was 105w+ per plant. Blue and white light promoted growth, then its best to change to a red and blue light during flowering stage. But This information has just wiped the slate clean of what i thought i knew, and now im back to knowing stuff all lol. Soo... if red colored lights are required during the "growth" period, how can people have such great growth using just your standard 130W 6400k fluero light? IF using CFL then what do growers usually use during the flowering period? do they change light setups, or just less powerful fluero lights such as 130W 2700k lights?
So let me get this right, for vegging, I need a cfl that uses 200 actual watts that puts out 2500 - 3500 lumens and for flowering I need a hps that uses 200 actual watts and puts out 5500 lumens? Is this accurate?
Plant lighting should be based on DLI... Daily light integral.... not watts, not lumens but PPFD. Each plant has a different DLI and this breaks down to how many Moles per day of light the plant needs for optimal growth. Cannabis has a DLI from what I have gathered of 22-30 mols/day and some sources have said as high as 43 mol/day... Now when you break it down this comes out to a PPFD per hour of the daylight time that your plants should be recieiving. A DLI of 22 equals... DLI requirement of 22-30+ (255 Umol - 347 Umol) PPFD on 24 hours daylight schedule. (383 Umol - 520 Umol) PPFD on 18 hours daylight schedule. (510 Umol - 694 Umol) PPFD on 12 hours daylight schedule. Now what does this mean... If you are flowering your cannabis plants....the entire canopy should be recieving at least 510 uMol or more for optimal growth.... If you are vegging with a 18/6 schedule then the lights don''t need as much intensity, as the plants are recieving more light because of the extended schedule, so for veg, optimal lowers to only 383-520umol... So what you need to do for accurately finding the right light is look at the PAR chart over a 4x4 area... see how the PPFD spreads for the light. The chart will show you how many lights are needed, what spacing and if the light will be sufficient for your grow area.... This is probably the most accurate way of planning out the optimal lighting for your garden. Yes plants will grow under 510 umol and you still will get buds, but for "optimal" lighting, the DLI method should be used. I belive photosynthesis starts for most plants around 50 umol, so anything more than this will drive photosynthesis, but for sun loving plants like cannabis, for the buds you want you need higher PPFD.