Do LED’s promote cal-mag issues

[Delps8]

Back to the topic of lighting spectrum and intensity effects on quality…

Many people have cited Dr. Bruce Bugbee & Mitch Westmoreland talking about the effects of light spectrum on secondary metabolites, or the lack there of… I just watched the Bugbee/Migro podcast from earlier this year where Bruce said they found no cannabinoid differences between different lighting spectra, though from his own study the results show a 10% difference in CBD between HPS & LED (no difference in THC) but whatever.

I know I’ve mentioned it before and I’m likely going to ruffle some feathers, but theses dudes are NOT the ultimate authority on cannabis science. Some of what they say just isn’t representative of drug type cannabis (they both grow non-THC hemp), and their methods serve to show the shortcomings of not only their experiments, but the conclusions one can draw from them regarding drug type cannabis.

For some time, Bugbee's research was restricted to low THC cannabis but the Federal Government changed licensing and he's been using standard strength cannabis for a few years now. I think it's been a few years but I can't cite a source for that.

 

[cdgmoney250]

For some time, Bugbee's research was restricted to low THC cannabis but the Federal Government changed licensing and he's been using standard strength cannabis for a few years now. I think it's been a few years but I can't cite a source for that.

It was actually from this video starting at 13:00 minutes in where he’s talking about it. Granted the video is 5 years old, he makes a statement in the migro interview from earlier this year basically telling people to prioritize electrical efficiency over spectrum, but that misses the point of growing a medicinal crop if we don’t cultivate all the possible compounds each plant has to offer. An electrically efficient spectrum might grow subpar plants compared to a more broad and balanced spectrum, which is less efficient. Just gotta decide which is more important.

 

[DoubleD5374]

From my personal experience , They absolutely demand more in my setup . I believe it’s magnesium but don’t quote me on it . I actually have to dial my main nutes back , to allow more calmag , to keep my four auto flowers in coco loco / 9 gallon xxl autopot system and a kind x750 wide open on the full spectrum and currently 50% on the uv /ir . I had the same experience with 60/40 coco/perlite last grow as well .

 

[cdgmoney250]

Sounds like a cation imbalance in your coco. Potassium (K) and Sodium (Na) are highly competitive with Ca and Mg, and coco coir happens to naturally come loaded with K and Na. It’s usually why coco has to be buffered with calcium prior to use. This seems to be a more prevalent issue with people growing in soilless media following feeding guidelines, at least to me anyways.

 

[DoubleD5374]

Sounds like a cation imbalance in your coco. Potassium (K) and Sodium (Na) are highly competitive with Ca and Mg, and coco coir happens to naturally come loaded with K and Na. It’s usually why coco has to be buffered with calcium prior to use. This seems to be a more prevalent issue with people growing in soilless media following feeding guidelines, at least to me anyways.

coco loco , is treated as soil . It’s not pure coco . Also the issue presents itself to the two very large autoflowers closest to the led - but the two shorter plants don’t have it .

 

[cdgmoney250]

coco loco , is treated as soil . It’s not pure coco . Also the issue presents itself to the two very large autoflowers closest to the led - but the two shorter plants don’t have it .

You can treat it however you want, but it’s still primarily a coco/perlite mix with a dash of forest humus and EW Castings. That means 50-60% of your media likely has a K & Na imbalance and will have more difficulty holding on to Ca and Mg due to this competitive nature. This means your base cation saturation ratios of your media are possibly out of balance too.

Plants closer to the light will have higher nutrient demands due to higher metabolic rate. If the nutrients aren’t readily available for uptake, the plant will show deficiency in the nutrients it’s having difficulty up-taking.

Magnesium is mobile within the plant and deficiency typically presents itself on older leaves due to nutrient translocation to newer growth.

The most common cause of these “I switched to led and now my plants are deficient” symptoms are usually transpiration related issues (your environment) or fertilizer imbalances.

 

[Delps8]

It was actually from this video starting at 13:00 minutes in where he’s talking about it. Granted the video is 5 years old, he makes a statement in the migro interview from earlier this year basically telling people to prioritize electrical efficiency over spectrum, but that misses the point of growing a medicinal crop if we don’t cultivate all the possible compounds each plant has to offer. An electrically efficient spectrum might grow subpar plants compared to a more broad and balanced spectrum, which is less efficient. Just gotta decide which is more important.

Thanks for digging that up.

Ironically, I did a screenshot of that part of the presentation on "2022-05-01_09-49-10_PM".



"An electrically efficient spectrum might grow subpar plants compared to a more broad and balanced spectrum, which is less efficient. Just gotta decide which is more important."

"might"-no doubt about it. There might be a spectrum that doesn't grow "subpar" plants and, if there is, I'll be happy to make room in my tent!