Gpw average???

PerroVerde · Aug 30, 2016

doz said:
Here we are 13 posts deep and everyone is talking about PPFD and wattage.

Bigger than your light source is your plant genetics. Every plant is different and each pheno is different. Under a 600w CXB3590 setup in a 4x4 area, I grew 1.2GPW total (not including microbuds garbage pile, and fully trimmed not this half ass bullshit of weighing on the stick with fan leaves still intact like many do around here). In that setup, I had 6 plants. One strain is known to yield more and it sure did almost by 75% more. If I grew the same strain throughout, my yield would have potentially been 1.5gpw or even more.

GPW (really your total grow weight) can be used to measure the differences provided you utilize 2 grows comparing different light sources but thats about as far as it goes. It really is a poor measure of how well your garden did. One guy can grow with 1000PPFD with a low yield strain and another grow with 500PPFD with high yield strain and they come out even. So who did better?

Stupid....

So my best harvest under 400 cob watts in a meter squared area with 16 plants from clone, purple kush x blueberry cross in coco / 940 PPFD was a little over 20oz of high quality bud. That comes out to 1.4 gpw or 1.89 ounces per square foot... it can still and always be improved on...

jeepster1993 · Aug 30, 2016

My best harvest was:
250 watts of 3500K Cree led's in a 2 by 2.5 foot(5 square feet) tent. Growing Greenhouse seed co. femed Super Lemon Haze seeds in a flood and drain.

297 grams
1.2 grams per watt.

doz · Aug 30, 2016

PerroVerde said:
So my best harvest under 400 cob watts in a meter squared area with 16 plants from clone, purple kush x blueberry cross in coco / 940 PPFD was a little over 20oz of high quality bud. That comes out to 1.4 gpw or 1.89 ounces per square foot... it can still and always be improved on...

I agree that most of us can improve. I dont run CO2 so I know there is room for improvement. All I am saying is strain matters MUCH more than people think. There are high yielding strains out there that can push 800+ G/M2 and then theres some that only throw down 3-400 G/M2. Thats less than half for some strains no matter the light source.

That said, I have yielded 1.2gpw each grow with LED so far and I know it can be improved upon. I am anxious to see what this run with 400w of CXB3070 @ 45.5% and 600w of CXB3590 @ 56% does. I am running bare cobs as well so there is a little bit of loss there too.

churchhaze · Aug 30, 2016

My best so far was 306.5g in a 2'x4' with 193W of cxb2530 3000k 80cri U2 bin.. I could raise ppfd to get more g/sqft at the cost of gpw... While I agree that GPW isn't really a great measurement, I get the feeling that the people against it the most are just defensive about their GPW.

Greengenes707 · Aug 30, 2016

We pay for KwH's, not simply watts. And the same applies for lighting yield calculations. How much energy did you use on your plants? G/KwH tells you that...g/w does not.
G/sqft is also a great metric for production.

insanehq · Aug 30, 2016

Thanks for all the replies and all the info, i think ill run my 16 cobs at 600w and go from there and the next run i might go lower or higher and just work it out with the strain i have

insanehq · Aug 30, 2016

PerroVerde said:
So my best harvest under 400 cob watts in a meter squared area with 16 plants from clone, purple kush x blueberry cross in coco / 940 PPFD was a little over 20oz of high quality bud. That comes out to 1.4 gpw or 1.89 ounces per square foot... it can still and always be improved on...

Great stuff man this is my first cob run, ive used hps and mars1200 before this, im sure this run will be alot better the spread of light is what i like hope i can get over 600grams in my 4x4

benbud89 · Aug 30, 2016

I agree that the balance should be placed between g/kw and g/sq ft. The balance inbetween those two variables is what matters, and then knowing your genetics. That being said, Im not that great of a grower and still on my first run with my new DIY lights. I would tell you to use 30 or 40w/sq ft and make the space according to that, in agreement with the idea of diminishing return. I hope you have fun, thats what its really all about.

PerroVerde · Aug 31, 2016

insanehq said:
Great stuff man this is my first cob run, ive used hps and mars1200 before this, im sure this run will be alot better the spread of light is what i like hope i can get over 600grams in my 4x4

Welcome to the cob cult...

be sure to have cal/mag at the ready, I use double the cal/mag that I did with hps now with cobs... good luck and I'm sure you will be pushing 2 in a 4' x 4'...

Hybridway · Aug 31, 2016

CobKits said:
no provided you have at least enough light to make non-larf, less light will always yield more in GPW (depending on light tech- with HIDs larger bulbs are more efficient. with cobs, the same nmber of cobs run at 400W is 10% more efficient off the bat than run at 800, and youre also in a a more efficient use of light because of this (which keeps coming up, 3rd time tonight):

That's not the Rahz/Tasty chart is it?

Hybridway · Aug 31, 2016

PerroVerde said:
Welcome to the cob cult... be sure to have cal/mag at the ready, I use double the cal/mag that I did with hps now with cobs... good luck and I'm sure you will be pushing 2 in a 4' x 4'...

I don't get why you say they need more cal-mag for cobs? I thought that was a Burple thing. It's an led in general thing? I don't use anymore then my HPS run. Hu!?!

insanehq said:
Yeah i have cobs alread man ive seen the light haha, lets say 4x4 800w cob and a 400w cob grown exactly the same will they yeild same gpw? Or will lower or higher watts give better gpw? Same strain same everything?

If you're a good grower w/ enough healthy plant to go around, 800w or 50/sq' is going to yield you the most. For an experienced grower w/ good producing strain, it's the magic #.
If your skills are hobbyist & your plants are medium sized then you would be best off to maximize GPW w/ around 600.
Although my SE-450 will put out a ridiculous GPW in a 4'x4', so maybe. But that's enhanced white. Straight white cobs, prolly 600w.
More pot is way more important then GPW though. Some guys talk about the sweet spot. Which is why I said 600. I believe in max yields, why I said 800.
Max GPW could be around 450 though. I wouldn't risk it if I didn't have to.
Here's 3 plants under 450+100 doing great. But I'll be adding 400 to that this week cuz it's just not enough for me.

dro-man80 · Aug 31, 2016

Hybridway said:
I don't get why you say they need more cal-mag for cobs? I thought that was a Burple thing. It's an led in general thing? I don't use anymore then my HPS run. Hu!?!

If you're a good grower w/ enough healthy plant to go around, 800w or 50/sq' is going to yield you the most. For an experienced grower w/ good producing strain, it's the magic #.
If your skills are hobbyist & your plants are medium sized then you would be best off to maximize GPW w/ around 600.
Although my SE-450 will put out a ridiculous GPW in a 4'x4', so maybe. But that's enhanced white. Straight white cobs, prolly 600w.
More pot is way more important then GPW though. Some guys talk about the sweet spot. Which is why I said 600. I believe in max yields, why I said 800.
Max GPW could be around 450 though. I wouldn't risk it if I didn't have to.
Here's 3 plants under 450+100 doing great. But I'll be adding 400 to that this week cuz it's just not enough for me.
View attachment 3769833

very interesting about your take on cal/mag...
So far myself and a few other fellas I know that have converted to Cobs,are in agreement that not only did the same strains require more cal/mag then when ran with HPS,but also higher feeding then normal with HPS..
I wonder why u dont have tht issue?

I wonder is it a certain genetic trait in certain strains or something,,,,huh??
All being said,I enjoy watching ur grows and think u do a great job representing the :arrow:

COBs lol..
much love and peace :peace:

Hybridway · Aug 31, 2016

dro-man80 said:
very interesting about your take on cal/mag...
So far myself and a few other fellas I know that have converted to Cobs,are in agreement that not only did the same strains require more cal/mag then when ran with HPS,but also higher feeding then normal with HPS..
I wonder why u dont have tht issue?
I wonder is it a certain genetic trait in certain strains or something,,,,huh??
All being said,I enjoy watching ur grows and think u do a great job representing the COBs lol..
much love and peace

Thanks bud!
I always thought the cal-mag boost was needed due to deficiencies in Burple spectrums!
But I don't know allot about growing w/ Burple so idk.
I use 2 ml a gal. Of Cal-Mag w/ my regular feed schedule in both rooms. HPS & led. No differant for me. They both drink about the same. White Led drinks fast due to the complete full spectrum allowing better uptake & the HPS drinks fast due to a higher leaf temp.
That's just what I believe though.

Growmau5 · Aug 31, 2016

CobKits · Aug 31, 2016

pop22 said:
Seems there must be a better way to determine productivity, maybe gr/sq.ft? then it isn't just about the light, its about the garden as a whole. Even then, if you switch up strains often like i do, the numbers don't mean much unless you collect your data for each strain you grow more than once. Seems to me that consistency should be our primary goal, the improve upon that.

nothing other than g per total kwh is really relevant. gpw is meaningless if you paid the electric bill to veg for 6 mos to get there

Shugglet · Aug 31, 2016

G/Sqft describes how efficiently youre using the space of your grow.

G/w describes how efficiently youre using the electricity going into your grow. (This should be the total watt usage of your entire grow, not just your light)

So, [(g/sqft)/(g/w)] = efficiency ratio of your grow. The lower the ratio the better. Quick someone check to make sure I didnt make any dumb errors.

Growmau5 · Aug 31, 2016

Shugglet said:
[(g/sqft)/(g/w)] = efficiency ratio of your grow

g/sqft divided by g/w yields units of watts per sqft... how does that metric relate to efficiency.

30 g/ 1 sqft divided by 1.5 g/ 1 watt gives 20watts per square foot. i dont really follow.

metrics that describe an "efficiency" of something are typically unit-less. to be expressed as a ratio.

purplehays1 · Aug 31, 2016

insanehq said:
Weird post but just wondering on people experience on the best gpw, eg what would yeild the best gpw among these circumstances
1plant 1000w,600w,400w,200w,100w,
Obviously there is limit to where light intensity comes into it, is it better to do 2 200w setups or 1 400w setup, cobs have efficiency and i believe plants will also have some kind of efficiency aswell, does your gpw suffer after 1000w or more, or is the best gpw ratio achieved at a lower wattage like 200w?

i have a 2ft x 2 ft tent so cant use it to the full potential, but i run 400w HPS and best yield has been about 1g/w maybe 1.1g/w. I think with 3ftx3ft i could yield 1.5g/w easily.

tomate · Aug 31, 2016

Shugglet said:
G/Sqft describes how efficiently youre using the space of your grow.

G/w describes how efficiently youre using the electricity going into your grow. (This should be the total watt usage of your entire grow, not just your light)

So, [(g/sqft)/(g/w)] = efficiency ratio of your grow. The lower the ratio the better. Quick someone check to make sure I didnt make any dumb errors.

There is one big flaw in ur math. U didn't take time into account.

So like @Greengenes707 and @CobKits already said, g/kWh is the only true and meaningful unit of measurement.

Illinois Enema Bandit · Aug 31, 2016

CobKits said:
gpw is a misnomer

a person could throw clones in and run them for 8 weeks under 1000W and get say X grams
a person could veg for 8 weeks under 500W@24 hrs and flower them for 8 more weeks under 1000W and get 1.5X grams

which was the better deal?

I was thinking the same issues,I half expected this to be a sea of green thread,which IMO is the only case where gpw is valid,fresh rooted clone to day 1 of 12/12 at 60 days maturation is the only way gpw works out

Gpw average???

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