#### Marzbadrock

##### Plant of the Month: Sept 2015 - Nug of the Month: Jan 2016, May 2018

Or 4.20 grams a day but that probably wrong to!

- Thread starter Rider509
- Start date

Or 4.20 grams a day but that probably wrong to!

It's basic math! How do 17 grams a day for 63 days equal 686?He argues to argue. LOL

Has a problem admitting he is wrong. But that's cool. That is what our world is made of.

The problem you're having with the math is that it doesn't work with fractions of a light. If you divide by .63 you get a bigger number than if you divided by >=1. You would have to multiply it there to get a smaller number.So see if I have this correct. I am running two 315W CMH's, so that is 630W. That is 0.63 of 1000.

So my formula would read, Yield / 0.63 / Days = G/day.

686/0.63/63 = 17.3 gram/day.

Is this correct?

GR

686*0.63/63 = 6.86 G/L/D.

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This is like the lady at home depot telling me a 16 in by 16 in tile was 1.5 sq ft

Hey sorry everyone ! I really wasn't trying to cause a ruckus. I wasn't trying to disagree with the per light , per watt nothing like that. I seen something that is wrong to me, let's just agree to disagree. Smoke a bowl n have goodnight everyoneThe problem you're having with the math is that it doesn't work with fractions of a light. If you divide by .63 you get a bigger number than if you divided by >=1. You would have to multiply it there to get a smaller number.

686*0.63/63 = 6.86 G/L/D.

Maybe rider can just clear something up for me so i know. Maybe I'm just missing something obvious.I read an interesting article by Ben Burkhardt, who once owned the largest indoor grow facility in the country. He found that there was no simple metric for yield analysis which took into account not only the power used by lights but also the length of flowering time. Often yield is stated as grams per watt, but that doesn't take into account the difference between a plant that finishes in 45 day versus a plant that takes 90 days. He put forth a metric that takes both into account and works for the closet grower as well as a huge commercial grower, and returns a number that can be compared across any grow type.

The equation is as follows: Yield in grams ÷ number of 1000W lights ÷ days in flower = GPD average.

As an example, my three plants were under 1600W of leds and took an average of 90 days, and yielded 3000 grams of dry flowers.

3000g ÷ 1.6 ÷ 90days = 20.8 grams per day.

Here's a link if anyone would like to see the source material.

Grams Per Day by Ben Burkhardt.

20.8 per 1000w used?

33.3 grams a day for 1600w

This is some brilliant shit! If Stephen Hawking could read this thread he would just.. oh yeah he already did.

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I believe it is call Extrapolation!

Example

20.8 is to 1000 W = X is to 1600 W. Just cross multiply and divide.

So 20.8 x 1600 = 1000 X so,

20.8 x 1600 equals 33,280 divided by 1000

So, X = 33.28

Not a math teacher so I hope this made sense.

First thing I noticed is Ben is not saying grams per day per light at the end of his equation, and the equation is for gram per light per day.

Here's a clip from his article

In order to account for both the flowering time and the weight yielded from a particular batch, I developed a simple and useful system of data analysis of true yield results and trends. First, the number of 1,000-W lights used in the batch is determined. Then the total grams of dried manicured flowers and the days of flowering time are assessed. The equation is as follows: Yield in grams ÷ number of lights ÷ days in flower = GPD average.

Here’s an example: 1,000 grams yielded ÷ 1 light ÷ 70 days in flower = 14.29. So this single light’s crop had a gram per day (GPD) average of 14.29. No matter how large or small a crop is, it can be measured as such, allowing an equal playing field of crop analysis irrespective of crop size or time it takes to flower particular genotypes. Here’s another example from a larger batch: 58,453 grams yielded ÷ 75 lights ÷ 67 days in flower = equals 11.63 grams per day.

Let's look at his first example 1000grams ÷ 1 light÷ 70 days = 14.29 grams per light.

Does not matter if that was a 10 watt or 10,000watt he got 14.29 for that light

His last example. by his numbers he gets 11.63 grams per day? Pretty horrible off 75 lights lol.....obviously that's 11.63 per light per day even though it says grams per day.

So if we substitute a 500 watt light in his first equation for the 1000watt then the new equation going by what was posted earlier would be

1000grams ÷ .500 ÷ 70 ?

Doing this does not work, it doubles his grams per day.

The equation should be

1000grams ÷ 70 days= 14.285 gram per day

Exactly what I just posted above weasels post

I believe it is call Extrapolation!

Example

20.8 is to 1000 W = X is to 1600 W. Just cross multiply and divide.

So 20.8 x 1600 = 1000 X so,

20.8 x 1600 equals 33,280 divided by 1000

So, X = 33.28

Not a math teacher so I hope this made sense.

I'm sorry! With the ? behind 1000 W used, I thought your were asking a question.Exactly what I just posted above weasels post

He got 33.3

I was just clarifying that was 20.8 per 1000w

You stated above

He got 33.3

I was just clarifying that was 20.8 per 1000w

"Let's look at his first example 1000grams ÷ 1 light÷ 70 days = 14.29 grams per light.

Does not matter if that was a 10 watt or 10,000watt he got 14.29 for that light"

If you reread the article, he states 1 light is 1000W.

I'm saying if you his example with a smaller light it doubles his harvest weight.

??????

I'm saying if you his example with a smaller light it doubles his harvest weight.

So that would be 1000÷ .63 ÷ 70

That's using his formula with your light.

That would mean he averaged 21.97 using your light?

But say he used 400W, 400 divided by 1000 equals 0.4, so the formula becomes.

1000 / 0.4 / 70 equals 5.71GPL

Wouldn't it be 35?

But say he used 400W, 400 divided by 1000 equals 0.4, so the formula becomes.

1000 / 0.4 / 70 equals 5.71GPL

So 1000÷70 = GPD ÷ watts = gram per watt.....right?

yes your correct, math error.