New Grower GPW...What?

[Hazy]

Ok this has bothered me for a little while, and i have been guilty of using GPW myself. Here's the thing it's not really a measure of efficiency.

I'll try to explain. If A grows 500g under a 600w light in 70 days and B grows 500g under a 600w light in 100 days their GPW are the same. This of course makes no sense as a measure of efficiency.

First lets look at A. 600w x 20hrs = 1200w per day x 70 = 84000w. Then divide this by 500g = 168w to produce one gram.

Now for B. 600w x 20hrs = 1200w per day x 100 = 120000w Then divide by 500g = 240w to produce one gram.

This is the true measure of efficiency of the two grows, A only uses 168w to produce a gram whereas B uses 240w to produce one gram. That's a difference of 72w per gram between A & B. Making grow A more efficient by producing the same amount as B but using 36000w less power to do so..

Hope this helps to explain why GPW should not really be used as a measure of how good or not a certain light might be.

Just trying to keep us honest

 

[TaNg]

What if it's used to measure personal achievement? Let's say over a 12 week period with a 20/4 light cycle I grow 360g with 360w then the next 12 week grow in the same room with the same light cycle but different lights and I get 400g from 240w...to me I think its a handy bit of maths if the parameters are set right.

 

[cres]

I have long said the very same hazy. Its all in the math weather you figure it right. And a grow from seed for a photo at 12/12. Will also change the math more in the favor of less watts.

So tang your watts have dropped also by going 18 instead of 20... more grams per watts. You can plug your datta in the same as hazy to find out how your grow at 18 is even more productive then 20....

 

[Hazy]

What if it's used to measure personal achievement? Let's say over a 12 week period with a 20/4 light cycle I grow 360g with 360w then the next 12 week grow in the same room with the same light cycle but different lights and I get 400g from 240w...to me I think its a handy bit of maths if the parameters are set right.

I absolutely agree with you in that context TaNg . as i said i'm guilty of using it myself. I was just trying to show a way to measure the true efficiency of each grow. :Sharing One:

 

[Magic]

Great info guys soaking all this up! :Sharing One:

 

[Hazy]

I have long said the very same hazy. Its all in the math weather you figure it right. And a grow from seed for a photo at 12/12. Will also change the math more in the favor of less watts.

Nail on the head cres... This is what i was getting at, to make autos efficient you really need to be bringing them home in around 70 days, which puts them almost on a par with photos(photos still win slightly) but once you start going beyond this point, you are using more power to produce the same amount of bud that you would in a photo grow. :Sharing One:

 

[Lardy]

This is all great but it takes no account of strength - only weight.
I personally would rather produce 1 ounce of good weed to 2 ounces of run of the mill - or buy if I had to.
Were it a commercial enterprise, some people will pay double or more for the good stuff. You must have seen "Breaking Bad".
This is not a measure of efficiency in financial terms in my humble opinion ofcourse.

 

[Epic Genetics]

Ok this has bothered me for a little while, and i have been guilty of using GPW myself. Here's the thing it's not really a measure of efficiency.

I'll try to explain. If A grows 500g under a 600w light in 70 days and B grows 500g under a 600w light in 100 days their GPW are the same. This of course makes no sense as a measure of efficiency.

First lets look at A. 600w x 20hrs = 1200w per day x 70 = 84000w. Then divide this by 500g = 168w to produce one gram.

Now for B. 600w x 20hrs = 1200w per day x 100 = 120000w Then divide by 500g = 240w to produce one gram.

This is the true measure of efficiency of the two grows, A only uses 168w to produce a gram whereas B uses 240w to produce one gram. That's a difference of 72w per gram between A & B. Making grow A more efficient by producing the same amount as B but using 36000w less power to do so..

Hope this helps to explain why GPW should not really be used as a measure of how good or not a certain light might be.

Just trying to keep us honest

plus rep

hopefully people get it finally

 

[cres]

Nail on the head cres... This is what i was getting at, to make autos efficient you really need to be bringing them home in around 70 days, which puts them almost on a par with photos(photos still win slightly) but once you start going beyond this point, you are using more power to produce the same amount of bud that you would in a photo grow. :Sharing One:

I often wonder if a 1m x 1m tent/grow area with a single light, yields more than a 1m x 2m tent with 2 lights. As that extra side of the tent adds 25% more reflexive area, so 2 1m x 1m tents would have a significant advantage 50%. So if you had a large room with 4 tents it might be a far better yield then if they were all in one room under multiple lights...

 

[Epic Genetics]

I often wonder if a 1m x 1m tent/grow area with a single light, yields more than a 1m x 2m tent with 2 lights. As that extra side of the tent adds 25% more reflexive area, so 2 1m x 1m tents would have a significant advantage 50%. So if you had a large room with 4 tents it might be a far better yield then if they were all in one room under multiple lights...

i believe the multiple lights helps a lot , reflected light , shared/added light etc

peace