Rahz' notes and observations

OneHitDone

OneHitDone

Well-Known Member
I notice @Greengenes707 is paying attention to this thread.
What is your opinion on the importance / benefit of ratio's of Red : Far Red on Cannabis bro?
I notice you are designing lights with red enhancement now and there is obviously a reason.
 
nfhiggs

nfhiggs

Well-Known Member
nfhiggs said:
Emerson himself noted that it falls off in strong white light - at least thats my understanding. I'll try to dig up some references...

off I go....
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I could not find where I first read that, but I did find this paper:
http://www.plantphysiol.org/content/plantphysiol/39/1/10.full.pdf

And here is a relevant screenshot from it:

emerson.jpg

You can see the enhancement curve drops to nothing in the bottom left chart. And in the bottom right chart the effect declines as light intensity increases. Absolute light levels are not given in the charts, but if you read the text below, it appears the intensities are pretty low compared to what we generally grow with.

IMHO, chasing the Emerson Effect, like chasing "the perfect spectrum" is a fools game. For one thing, it a rather small increase in a rather small section of the PAR spectrum - when compared to the overall photosynthesis picture (when using white light) it just does not add up to a hill of beans.
 
nfhiggs

nfhiggs

Well-Known Member
Baura said:
I don’t buy shitty tires, neither shitty brake components for my car. There are some things I won’t mess with.

I won’t buy chepo leds and drivers.
I’m using GE immersion led drivers(for refrigerated led lightning) for my 048-1812(50v 1.2a) I found them cheep enough(u$15 each driver here in Brazil) and GE a reliable brand, not a meanwell 96%eff, but good enough. This was the best $/w I found on a reliable driver locally sourced.

Wen I said the best ppf/$, I’m not going “full retard” on numbers. Quality and reliability are a must.

I’m seeking the best $/ppf with quality components.
Aiming high efficiency (2.5 umol/J) gets really expensive here in Brazil. I believe 2-2.2 umol/J might be a good target in third world countries
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I have a bunch of said "shitty leds" (COBs) and I've yet to see one fail. Failure is just not the issue with them, its their efficiency.

And the Acuity lights are a genuine Samsung product - just not the high efficiency of the F-strips.

BTW, Mean Well makes LRS series power supplies, that you can get for a little over 10 cents per watt - about 1/3 the price of their HLG drivers. I looked up those GE drivers and most sources had them at $.35-$1.00 per watt.

As we say here in the US - there's more than one way to skin a cat.
 
Rahz

Rahz

Well-Known Member
Just wanted to mention after seeing some price figures lower in the thread that if I could get the same output per watt by running more Vestas at lower current, for the same price, then I would consider using them. I don't really keep up with new products/pricing like I used to.

Rocket Soul said:
Thanks Rahz, its wonderfull to see theres still people doing stuff like this, side by sides etc and sharing results.

As you like your high CRI spectrums, what do you think about this one?? Its bridgelux Vesta strips, 2 channels: 5000k / 2700k both in 90 Cri. The red line is samsung 3000k 80cri. I like how the whole spectrum looks more flat than the standard 80/90 cri that have more of a peak. 660nm at 80% of max, 680nm at around 50% of max. The question id like to pose is rather than trying to fit in as much light as you can on the most efficient wavelengths, does it make more sense to try to distribute the spectrum more wide, over all of the different pigments, while at the same time maintaining high output in reds, even those 680-700nm which are normally missing in phosporbased leds.

I know the efficiency of these chips are low comparde to sammies and some cobs, but you can allways get more light with more power.
View attachment 4154392
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eyderbuddy

eyderbuddy

Well-Known Member
Baura said:
Agreed, but when the budget is short(my case), ppf/$ maters more than efficiency.

as randonblame posted,

The vesta are $9 and 112ppf = 12ppf/$
The f-series are $27 and 131ppf = 5ppf/$
and
The eb g2 are $6,5 and 32ppf = 5ppf/$


but if the high cri have more red and far red, the ppf number does not take in account the emerson effect right?


Like, if we supose that:
- a certain led 3000k 70cri has 100ppf
- a certain led 3000k 90cri has 100ppf


The ppf number is the same, but wouldnt the emerson effect make the 3000k 90cri "give" more energy to the plant?
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Where are you getting this data from? you seem pretty sure quoting 12ppf/$, 5ppf/$ and such... I'm just trying to see if the match checks out.
 
Randomblame

Randomblame

Well-Known Member
Baura said:
https://ledgardener.com/forum/viewtopic.php?p=5325#p5325

Not my data , but made sense to me.

The eb ppf/$ I don’t remember where I got from, but when I get home I’ll take a look.

By the way, it seems that bridgelux will increase the efficiency of 90cri leds
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Hopefully also on their SMD2835's, announcement only mentioned Vero, VeroSE and V-series.(probably gen8)
There are far too few efficient CRI90 strips, it's about time that this changes. The 12 and 24v strips with 90-100lm/w are useless and the Vesta's currently the best ones out there.
 
Rocket Soul

Rocket Soul

Well-Known Member
Baura said:
By the way, it seems that bridgelux will increase the efficiency of 90cri leds
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Its also a good point to mention that 5% increase in luminous efficacy doesnt always equate 5% more photons, it maybe that the spectrum has been tweaked to give more lumens, but that ppf hasnt gone up a full 5%. But anyways its good news, especially if/when they do the strips aswell.

Edit: we are on Rahz thread and we might be going outside the scope of it, maybe this discussion is better somewhere else, ill let @Rahz chip in on this
 
KonopCh

KonopCh

Well-Known Member
Rahz said:
Also, I never run ppm over 1000. I do want to experiment one day, but you don't need outrageous TDS to pull good yield. In the past I kinda winged it based on recommendations, but after digging a bit deeper I've got to the point where I measure out nutrients by elemental ppms. General rule of thumb is 100-150 ppm Nitrogen for best vegetative growth. I've been shooting for 100 over the last couple grows but would like to play with bumping up closer to 150 during veg, could be especially helpful for getting bulk in the first two weeks if I'm going to shorten my veg period and maintain root ball size going into flower... but I wouldn't be surprised if going from 100 to 150 didn't produce a lot of difference.

As far as the P and K, range for P seems to be 20-100 and for K 150-250. In these hydro systems I've been keeping P at around 20 using CocosAB formula and then switching to 50 ppm at the start of week 3. I've been doing this because P (typically cited at +70 ppm) inhibits various beneficial microbes and I had some root rot issues and the rot doesn't seem to care what the P levels are. Now that I've got the situation under control I'm getting less paranoid and thinking 50 ppm P will be fine to start with, and again if I want a 2 week veg it makes sense to kick the P up ASAP.

I know less about potential min/max of K. I base my 250 ppm figure on adjusting nitrogen of various brands of vegetable fertilizer to 100 ppm and see what the K comes out to. If I bump the N up to 150 that can put the K as high as 375... but for perspective these are fertilizers intended for soil so it's going to get watered down to some degree as soon as it's applied. Analyzing hydro specific nutes at suggested rates, K can be as high as 275-320 and P as high as 150-185. Like a lot of people I have my doubts about running those numbers because I've had good success running much lower, but it's worth testing out right?

Anyway, I think it's worthwhile to work out the formulas for elemental NPK and base the fertilizer plan on NPK ppm rather than TDS. I like the Maxibloom/Maxigro dry combo because I can get just about any reasonable n/p/k ratio I want with a 2 part formula, it contains cal and mag which a lot of dry "complete" fertilizers do not, and it's cheap compared to liquid nutes. I have attached a simple NPK calculator I whipped together in Excel. The pic should explain everything, but you can also copy/paste or delete rows. If you add rows you will need to double click the elemental PPM cells and adjust the sums to include the new rows. For different ferts, just change the names and the guaranteed analysis values. You can load in a whole nutrient line or just check the elemental values for a one part formula.

View attachment 4111948
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Hello,

I found your nutecalc here on RIU. However, it's litte pain in the ass because I am from EU and we use liters. I don't know how to change your "gallons" to liters, can you help me please?
I tried dividing every number found in excell by 3.78 but it doesn't work like that.
 
Rahz

Rahz

Well-Known Member
KonopCh said:
Hello,

I found your nutecalc here on RIU. However, it's litte pain in the ass because I am from EU and we use liters. I don't know how to change your "gallons" to liters, can you help me please?
I tried dividing every number found in excell by 3.78 but it doesn't work like that.
Click to expand...
You would want to multiply the final values by 3.78. You could add a line below the values per gallon numbers to do it automatically. Another way, if you would rather just have the PPMs per liter listed is to go through the formulas in the right 3 columns and change every value from 264.17 to 1000.

The nitrogen formula for instance:
=SUM(264.17*(B4/100))*E4
Would change to
=SUM(1000*(B4/100))*E4

Or, if you wanted to simply the formulas and get the same result
=SUM(264.17*(B4/100))*E4
Would change to
=SUM(10*B4)*E4
 
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