True or False? For the pro's only

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ttystikk

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Growing with metal halides or lights with a high kelvin rating will force your plants to use more nitrogen. I say true !
Interesting hypothesis.

It's now possible to order or build lights that are identical in every way, save their spectrum output. COB LED and other newer generation LED chips can be ordered in a wide array of Kelvin temperatures, allowing for a very fine degree of control over your desired variable.

Consider running two fixtures, one at 6500K for high blue and the other at 2500 or 3000K for high red (also great for bloom, btw). If these fixtures are designed with the same number of the same type of chip, and operated at the same wattage with the same driver, then all that's left is two tents, some clones and substrate.

Two ways to tell which one uses more nitrate; use the amount of the same soil mix for both sides and watch for which one depletes its N first... or soil analysis after the fact.

Let us know what you find!
 

MichiganMedGrower

Well-Known Member
Yes but the fuller spectrum makes for more efficient photosynthesis.

So it's really back to the intensity vs the spectrum and for pure growth and nutrient needs the higher intensity light will likely burn more nitrogen.

IMO

I will know in time. I just added a 315 LEC to my flower room. It will be compared to my 600 Super HPS in many ways.
 

Dr. Who

Well-Known Member
While it can be theorized that the difference may be greater in veg then bloom. Or would it?....Just how much may this effect late bloom N use by the plant?
How much of that effect is present, and will that affect a decrease in concentrations of the THC related compounds, due to higher concentrations/use of the N in/by the plant, during this mid to late bloom period?

Oh to have a complete lab.....just to have fun with my time!

GREAT theory! Great follow-ups!

I feel the lack of a broader available spectrum in HPS is at fault for the longer bloom times found by many HPS users. I also feel that the same is responsible for the less positive finish found in the exclusive use of HPS lighting indoors.

Think mid - low wave blues and the UV bands too...These go a long way to achieving better indoor results and more positive finishing.
 

MichiganMedGrower

Well-Known Member
The Hortilux Super HPS bulbs have about 25% blue light to red. They grow very nice buds but as @Dr. Who mentioned I wonder about my long flowering times and although I am more than happy with my results this year I still chose the new fuller spectrum lamp to expand my room.

I want to say it "feels" better in there with the 92 CRI bulb mixed in.

I expect even higher thc and terpene content from buds finished under the full spectrum lamp.

We will see in a few weeks if finishing under it makes a difference.
 

Rayne

Well-Known Member
Generally speaking. More light intensity cause the plant to need more minerals rather than explicitly more nitrogen. Plus the type of nitrogen a plant needs in the flowering phase is different than what it needs during the vegetative phase.

Constantly adding more nitrogen than what the plant actually needs regardless of the growth phase causes nitrogen toxicity.
 

ttystikk

Well-Known Member
Generally speaking. More light intensity cause the plant to need more minerals rather than explicitly more nitrogen. Plus the type of nitrogen a plant needs in the flowering phase is different than what it needs during the vegetative phase.

Constantly adding more nitrogen than what the plant actually needs regardless of the growth phase causes nitrogen toxicity.
Huh? Nitrates are nitrates, whether in veg or at finish, no? The amount varies, but this is the first time I've heard someone assert that the type is different too?
 

ttystikk

Well-Known Member
Generally speaking. More light intensity cause the plant to need more minerals rather than explicitly more nitrogen. Plus the type of nitrogen a plant needs in the flowering phase is different than what it needs during the vegetative phase.

Constantly adding more nitrogen than what the plant actually needs regardless of the growth phase causes nitrogen toxicity.
He's specifically asking about spectrum effects, if I read his original post correctly. This is something I'd be interested in hearing more about, myself.
 

Rayne

Well-Known Member
Huh? Nitrates are nitrates, whether in veg or at finish, no? The amount varies, but this is the first time I've heard someone assert that the type is different too?
1. Going of off my botany notes...
Vegetative or bulking related growth energy: Calcium nitrate, potassium nitrate
Flowering related growth energy: Ammoniumium sulfate, ammonium phosphate

There is a reason why the vegetative nutrients and flowering nutrients are in different containers.

2. The first two words of my initial post within this thread are "Generally speaking." Faster growth generally requires more minerals, not just Nitrogen(N), Phosphorus(P), and Potassium(K).
 

Dr. Who

Well-Known Member
Huh? Nitrates are nitrates, whether in veg or at finish, no? The amount varies, but this is the first time I've heard someone assert that the type is different too?
True in a way but the plant will use different "sourced" nitrates at varying rates during growth.

Urea nitrates are broken down to ammonia nitrates and you need more to gain the same yield as ammonia based!

Actually, ammonia based nitrates (ammonium nitrate) yield better in field crops by like 3-5%.....I see no reason this doesn't transfer over to what we are doing here!

Ammonium Nitrate does not have near the loss due to evaporation (1-3%) that Urea nitrates do (just under 30%), and you can't predict the loss rate of the Urea!

Urea is subject to leaching at a far higher rate also. This is due to the plant using ammonium nitrates, at a more efficient/effective rate - you use less!

These are things I know from farming, yet apply to us also!

There are various other sources of nitrates also, and they have various N availability ratios. the way the plant uptakes them varies also.

Ummmm,,,there are the ammonium family chemicals....

Ammonium Sulfate

And then the phosphate group

Ammonium polyphosphate

Diammonium Phosphate

Monoamonium Phosphate

These are used at differing rates by the plant, and the diammonium Phosphate is a good starter nitrate for plants as it's more "available or better used" by young and early vegging plants..

So, yeah @Rayne is correct!

Just thought I might "elaborate" a bit on that!
 

Dr. Who

Well-Known Member
Going of off my botany notes...
Vegetative or bulking related growth energy: Calcium nitrate, potassium nitrate
Flowering related growth energy: Ammoniumium sulfate, ammonium phosphate

There is a reason why the vegetative nutrients and flowering nutrients are in different containers.

And he beat me to the punch with more direct application to his point!
 

MichiganMedGrower

Well-Known Member
I would like to add that using fertilizers that offer different sources of nitrogen and many different trace elements will grow plants healthier and they will produce more cannabanoid and terpenes.

Good organic grows prove this and I thought it would go with the above information and was worth adding.
 

ttystikk

Well-Known Member
1. Going of off my botany notes...
Vegetative or bulking related growth energy: Calcium nitrate, potassium nitrate
Flowering related growth energy: Ammoniumium sulfate, ammonium phosphate

There is a reason why the vegetative nutrients and flowering nutrients are in different containers.

2. The first two words of my initial post within this thread are "Generally speaking." Faster growth generally requires more minerals, not just Nitrogen(N), Phosphorus(P), and Potassium(K).
I was hoping you'd have some insight like this, thanks for sharing.
 
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