How light spectrum affects nutrient use in plant tissue...

[We Solidarity]

The d paps kick ass. I just fired one up last week.

Hell yeah. If you're using it for veg you'll also see a more rapid and vigorous flip when you go into flower. Three weeks in and I'm seeing less stretch and more stacking...also started using the epaps in flower I'm loving all the new lights

 

[mastagrowa]

Plants need red light to fully metabolize P. I switched to CMH bulbs for veg which give off a more balanced spectrum (lots more red than MH) and am never looking back.

Sorry, what's a CMH bulb? Compact metal halide?

 

[caveman4.20]

Ceramic base suppose to be not as hot traditional base I guess metal

 

[GoClutch]

Im about to do an experiment comparing various LED fixtures, and one of the things I'm interested in learning is how the various spectrums effect cannabinoid profiles. According to some of the LED companies, their profiles are leading to better profiles by allowing the plants to better absorb their required nutrients. I'm supposed to have access to testing labs for my samples, and I'm going compare the profiles from the lab analysis with their spectrum maps and see what can be learned. Its possible we may learn some solid information about how light spectrum effects cannabinoid levels and nutrient absorption.

 

[GoClutch]

whats yoru footprint on the 600's? When I ran mine I was running a 3x3 footprint and kept the canopy about 16-18" from the canopy.

I run a very similar setup in my bloom- two long rows of 600W HPS inside of large Adjust-A-Wing hoods, I center each one over a 3x3 flood tray, but allow an extra 6" on all sides of the tray for overgrowth so 1 600/ 4x4 area, 12-18" from canopy

 

[Capulator]

@We Solidarity

So yeah I put some GSC that had tons of red stems from a t-5 to a 315w (same distance same nutes) and the 315w made all the new growth come out bright green and no red petioles.

The t-5 was a 2' x 4' 8 light fixture (500 watts). All the bulbs were that spectra whatever that the fixture comes with.. Very blue/white. No red really.

Again leading me to my belief that GSC loves P, and NEEDS red light to utilize a bunch of it.

 

[Rhyno]

Phosphorus deficiencies can be due to Temperature, Environment, and Magnesium (. Higher elevated leaf temp causes the stomata to close, reducing transpiration, which reduces water usage. This in turn slows growth and phosphorus deficiencies have been seen under this stress. As well as under colder stresses when the soil temp drops below 60deg. the colder temp affects root extension and soil phosphorus uptake- warming tends to help. Now if your plant grows beyond the necessary pot size, it depletes the usable phosphorus in the soil and becomes starved of that basic element, causing a notable deficiency. Magnesium regulates uptake of the other essential elements and serves as a carrier of phosphate compounds throughout the plant, so a phosphorus deficiency will usually follow a Magnesium deficiency (CaMg).

SensiCloud is correct stating that HPS promotes increased Ca and P uptake.

Not sure if this was stated earlier, but medium is important as well. Coco binds with Ca ion.

~Rhyno

 

[caveman4.20]

Oh shit...^^^^^^ well said

 

[Rhyno]

Thanks Caveman...

 

[juniper]

Placing my canopy way too close to LED cause what appeared to be a localized iron or zinc deficiency. Raising the light instantly cured the problem. Trust me, it wasn't light bleaching, this was a whole different animal.

My belief is that either cell division rates were outstripping the plants ability to uptake certain elements, or, given that my LED unit produces different spectrums of light from individual diodes, and thus must be a certain distance from the plant to "blend" the spectrum, the light was too close and the plant received a very unbalanced light source, possibly affecting nutrient uptake.

I've seen snippets of info dealing with this and LED's but nothing conclusive. I'm certain the same principles would apply to HID light. Though, at too close with HID's I just get bleaching rather than localized deficiency.

 

[Rhyno]

The pics on page 1, I am almost certain is a Ca deficiency. The Ca ion is immobile and will show deficiency closer to the top of the plant. The pics on page 2, show more like a P deficiency.

~Rhyno

 

[john martin]

I mix LED with HPS and the plants directly under HPS yellow faster, while the plants directly under LED seem to stay much greener, BUT...

... the plants directly under the LED: Drink more water, Nug up faster and harder, Yield more, Look, smell, and taste better.

This off course is based on mixed spectrum though, never done LED by itself.

 

[caveman4.20]

That HPs is definitely helping. LED by itself will not perform aswell

 

[619ster]

Not sure what LED yall are speaking on. But if saying LED in general can't perform as well as hps, I beg to differ.

 

[john martin]

I rock Cali. Lightworks LED, but am also investigating Black Dog.

Cali. Lightworks has impressed me so far.

 

[caveman4.20]

Not sure what LED yall are speaking on. But if saying LED in general can't perform as well as hps, I beg to differ.

I'm just saying added HPs is helping vs no HPs with led

 

[bagseedwndrs]

I mix LED with HPS and the plants directly under HPS yellow faster, while the plants directly under LED seem to stay much greener, BUT...

... the plants directly under the LED: Drink more water, Nug up faster and harder, Yield more, Look, smell, and taste better.

This off course is based on mixed spectrum though, never done LED by itself.

I ve expierenced this with mixed led and cfl light too. much better quality ganj i think leds by themselfs wouldnt cut it.

 

[Medusa]

Whats your thoughts on taking plants from veg with mh into bloom few weeks with mh ...then switching to hps ...at last weeks of bloom returning to mh ...these are 600 in both bulbs ...I noticed a good stretch at first in bloom ..but compact node spacing ...hps they have bulked up ..at week 7 ... in one more week switch back to mh ....for sure mh is cooler ... my research says this increases frost at the end ...Does anyone have any experience with this method with noticeable results ? Thanks M

 

[altitudefarmer]

Been playing basically with that same schedule, Medusa. I can't say for sure it's noticeably better. They do not stretch as much under my Blue; I really thought it was due to it being somewhat lower PAR than the HPS next to it. The plants in the overlap always look the best, but those under straight HPS yield better. That Blue really brings the frost out early, it seems.
I will post better data when I control the experiment more. Too many variables right now.

 

[Skuna Tuna]

ive been switching bulbs. i run 400w mh first 2 weeks, 600w hps weeks 3-7 and finish with a 400w mh for weeks 8-9 fwiw. i like it everything i see from it. i run perpetual schedules in the same flowering room; by doing this, i also reduce power consumption by 200w for 4 weeks out of 8-9. shit adds up!