Cannabis Lighting Is My Thing

[Lowrider72]

Surely. Examples of cotton top can be seen here:

Sorry for the camera white balance problem in the first pic. All but one of these was turned around (CT eliminated) by increasing nute delivery.

Also, your tip burn may be a function of the root's exposure to the nutes. Coco has the slightest bit of retention. Have you tried flushing and if so, did the tip burn stop? All of this aside, if you are happy with what you are doing and the medicine is good for you, that's all that matters.

Those white cotton buds are light bleaching.
Too much light.

Interesting! I am pretty happy so far - it is my first grow, so I am sure that could be doing a lot of things better/smarter. But the girls are alive, and within a week or so of finishing. The end is in sight!

I did start to see some foxtailing on one gal - a Green Crack photoperiod. I don't think it is stress related, as the other girls are all fine. Temps and RH are in the zone, and no light-leaks. So I (and a couple of other guys here on 420 who are much more experienced than I am) am thinking that it is just "natural" foxtailing. The last variable I could think of is the red light, but you have alleviated that concern as well. Here's a pic, just for reference...



Thank you again.

Yours is foctailing caused by excess heat.

 

[BeanTownFan420]

Hi,

I used to post here but haven't in quite some time. I have seen lives saved, including family members, by cannabis and its derivatives. For the past 12 years, I have dedicated what little brainpower I have left to research and development of cannabis (and now hemp) lighting. I am really interested in spectrum delivery and its effect on terpene expression. In the interest of disclosure, I have a lighting company, but my goal is not to promote products, but rather, ideas that benefit everyone when it comes to this wonderful substance and the tons of possible positive uses. I look forward to some lively discussions about lighting and cannabis.

Jonnywatt

 

[BeanTownFan420]

My fav is sun light.

Bring me a shrubbery.

• BeanTownFan420
• Jul 21, 2019

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• BeanTownFan420
• Jul 19, 2019
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• BeanTownFan420
• Jul 19, 2019

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• BeanTownFan420
• Jul 21, 2019

 

[jonnywatt]

A few years ago, the thermal engineering of COBs left a lot to be desired. Ganging up chips in close proximity to each other risks shorter lifespans due to heat. Now higher-end LEDs can deal with the excess heat, so I think we'll start seeing some COB configurations that work well. When I design, select or review grow lights, I follow a 3xC's plan. 1) Color (spectrum), 2) Coverage (distribution/uniformity), and 3) Current (power). When deploying COBs, 1) COLOR: Make sure they are full spectrum (there are tons of scientific research papers and winning Cannabis, Emerald and ERRL/710 Cups that prove out use of full spectrum for THC potency and terpene expression - both key to top-shelf results); 2) COVERAGE: Make sure the COBs are arranged so as to provide even coverage across your canopy (also make sure there are enough of them), and; 3) CURRENT (POWER): Make sure you are driving enough light to your canopy. For example, in a 4'x4' grow with a full canopy, and if your COBs are producing light at, say, 65-90 lumens per Watt, plan on 1W of LED power for every gram of dried product (gm/W). For those that haven't already mastered it, after you gain some experience growing with solid-state lighting, this number will undoubtedly go up. I have a partner that regularly achieves 1.6gm/W.

I believe any lighting solution can work well if the 3xC's are followed and remember -

Lighting sets the potential for your crop!

The other 100 things you do when you grow is what makes a crop good, or great, but you need the potential to start with.

OK, that's my two cents.

Thanks again for the welcome!

Jonnywatt

 

[jonnywatt]

My fav is sun light.

Bring me a shrubbery.

• BeanTownFan420
• Jul 21, 2019

20190719_152141.jpg

• BeanTownFan420
• Jul 19, 2019
• 1

20190719_152246.jpg

• BeanTownFan420
• Jul 19, 2019

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• BeanTownFan420
• Jul 21, 2019

We want.............ANOTHER SHRUBBERY!!!

Great work!

 

[jonnywatt]

Those white cotton buds are light bleaching.
Too much light.

Lowrider72, I agree. There is too much light for the rest of the environment, mainly, amount of nutrients. Bleaching under the Sun is rare, and there is far more light (photons 2000micromol/m2/s1) being delivered by the sun than any indoor lighting solution (~400-1500micromol/m2/s1). We have almost always been able to reverse cotton top if caught early enough through increase of nutrient delivery, but no change in light.

Yours is foctailing caused by excess heat.

 

[Atomahawk]

OK, that's my two cents.

Thanks again for the welcome!

Jonnywatt

Love your explanations .... it's going to be cool reading your comments.
Not to take away .... I as a hobbyist love playing with lighting ... started with incandescent aquarium lights for growing aquatic plants ...to halide's for growing and propagating coral. Now it's LED's ... going to play with some combinations of cobs and/or led's. I grow a lot of plants for my garden ..love a quick start ... hate the power consumption of 1000w , 600w HPS/MH or T5 H.O. Just not efficient if you consider par/lumen per watt burned.

 

[The Bard]

Yours is foctailing caused by excess heat.

Thanks @Lowrider72. I don't think so. I have three photoperiod girls in the tent, and only one is fox-tailing. I think it is more genetic than heat-stress. Looks like that cultivar is prone to fox-tailing in late flower. Oh well, going to get the axe within the next few days. Thanks again.

 

[Nunyabiz]

For the past 3+ years I've been vegging under about 300w of predominantly blue spectrum light to get tight node spacing which works well with LST.
I slowly introduce more red spectrum and more PAR the closer I get to starting flower until the week prior to flipping to 12/12 I am running full spectrum at 600w.

 

[No Pain]

Welcome Back Johnny ! I have went from HID's to blurple to Full Spectrum Led's (sk series, I love em) lamps . I can tell you there is a definite difference in terp expression as well as the flavor and trich production . I love it ! I recently just listened to an interview with Dj Short and he briefly touched base on this ..now I feel like I have read it before ...anyway he stated that in his years he noticed that the blues ( metal halide lamps) brought out the sweet and the reds ( high pressure sodium) brought out the sour. In my opinion/takeaway is that with full spectrum (depending on saturation of the entire spectrum) you get all the plant has to offer in the sweet and the sour providing you with a well balanced profile and a fantastic product.