Grams per Day vs Grams per Watt

Leonardo de Garden

Leonardo de Garden

Active Member
Grams per watt is an almost silly way to try to calculate success. It unfairly favors long growth plants. Veg a plant for a half year - year or so and you can pull down an impressive grams per watt with little effort.

A much more useful number to calculate is Grams Per Day (GPD). Subtract the planting date from the start date to find the total number of days grown. Then take the weight of harvest, and divide by the number of days grown, to find out how much was produced each day. Calculating the GPD for each harvest will allow a comparison of the success of different grows even if the number of days for each is different.
 
Samwell Seed Well

Samwell Seed Well

Well-Known Member
sounds like you trying to find weight per time vegged vs weight per light used, you cant make your plant photosynthesize more, it only has so much light

to completely differnt ways to look at yield but very clever
 
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Dubdeuce

Well-Known Member
Damn Skippy Brah! I do agree that grams per day is a much more accurate way to measure success if you're talking about going head to head with GPD and GPW.

However, i believe there is an additional variable that needs to be taken into account when determining the ultimate success of your results -- grams/area. So now we have:

grams/area
grams/watt
grams/day

I believe the grams/area and grams/day are the most important part of the equation and have about the same weight in importance. It comes down how much room did you use and how quick did you get it done...because as far as wattage and electricity...ultimately it is inexpensive and is more or less disposable, but your time and space are finitely limited and thus hold a higher value in the equation.

If 2 people had identical #'s in g/area and g/day then it would come down to who used the least electricity and then nutrients, hell we could even go as far to say who did it using the least amount of equipment.
 
Huel Perkins

Huel Perkins

Well-Known Member
Grams per watt is still going to be the best way to judge the success of your yield. You can veg a plant for a year until its 10 feet tall and 10 feet wide but your yield is still going to be dependent on how much light you have. Without enough light you're going to have airy little popcorn buds everywhere on the plant that does not get direct intense light which in turn will take away for he plant's energy where the light is focused where the main colas would be.

The amount of light you have is ultimately what determines your yield, period.
 
ghb

ghb

Well-Known Member
grams per year per light is a good way to measure success. i can get a gram per watt easily with only one week veg from rooted clone.
 
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Dubdeuce

Well-Known Member
The amount of light you have determines your yield? lol. I don't care how much electricity you used, if you can achieve twice the grams per day, you are winning. Electricity and equipment costs are nominal compared to the return. The bottom line is that there needs to be a timeline accompanying that. Ok great, you got 1 gram per watt, like you said but it took you a year to veg and flower. If someone gets a g/watt in 60 days then they obviously win in the success department. If you don't take time into your equation then you're foolish -- time is the only thing worth anything on this planet.
 
thehole

thehole

New Member
Here is how I judge success in indoor growing. I weight up each plant after dried and cured for 2 weeks, if I don't have a half pound per plant I consider it not a success, over half pound is a success.
 
missnu

missnu

Well-Known Member
At the end of the harvest you just have to feel like all the money and time that went into that run was worth the amount you get at the end...sometimes you take a plant down and feel like an expert...other times you take one down and feel like a failure.
 
ru4r34l

ru4r34l

Well-Known Member
ghb said:
grams per year per light is a good way to measure success. i can get a gram per watt easily with only one week veg from rooted clone.
Click to expand...
This I would like to see, 1 plant, 1 week veg under 100W light and you can get 100g; you do understand that it's almost 4oz right?

regards,
 
Huel Perkins

Huel Perkins

Well-Known Member
Dubdeuce said:
The amount of light you have determines your yield? lol. I don't care how much electricity you used, if you can achieve twice the grams per day, you are winning. Electricity and equipment costs are nominal compared to the return. The bottom line is that there needs to be a timeline accompanying that. Ok great, you got 1 gram per watt, like you said but it took you a year to veg and flower. If someone gets a g/watt in 60 days then they obviously win in the success department. If you don't take time into your equation then you're foolish -- time is the only thing worth anything on this planet.
Click to expand...
Yes, the amount of light you have determines your yield. This of course means you've done everything else correctly, the amount of light you have is the ultimate factor in detirmining your total yield, period. As long as you're efficiently using the amount of light you have to work with and vegging the plants to the size needed to cover the amount of space the light covers it won't mater how how many plants you have, how much more veg time you add to grow them bigger or how much room space you add, you will yield roughly the same amount.

For example. Two different grow rooms both using a single 1000w light in a 20"x20" hood.

Room A. is a 6'x6' space with 4 plants vegged just long enough for the plants to fill out to a nice even canopy with wall to wall coverage.

Room B. is a 12'x12' space with 8 plants vegged as long as you want, get them as big as you can if you think it will help.

Let both rooms flower for 8 weeks and then harvest, the yield will be the same.

The difference is, Room A. has 27.7 watts per square foot of lighting which is about the minimum for optimum indoor growing and Room B. only has 6.9 watts per square foot of lighting.
 
Leonardo de Garden

Leonardo de Garden

Active Member
I still contend that grams per day gives the better data. Once you know the rate your garden produces, you can calculate your return on expenses used. For example, if you calculate the expense of running a larger light, or new nute line, you can measure your return and then knowing if it was worth it is a simple matter of expense vs improvement. If without factor "x" average harvest is .18 GPD, and with it is .23 GPD then you know that the improvement has to cost less than .05 grams of harvest per day to be worth it. If you want to measure the efficiency of a garden, it is the baseline to use, as it literally measures the garden production rate. It can be calculated for an individual plant or a whole garden.
 
DelQ

DelQ

Active Member
So doing grams per day, if I end up with 2000 grams and it took me 120 days to grow... I'm ending up with 16.66 grams a day? And that's under 2000W of lighting in a 10 x 10 room. Is that right?
 
Leonardo de Garden

Leonardo de Garden

Active Member
Right, 2000 grams divided by 120 day = 16.67 grams per day (GPD).

If your next grow is 1800 grams in 110 days 1800/110=16.36 and you will have done worse, but at 1850 grams for the same time, and you will have done better (1850/110=16.81).

Or for a lighting efficiency step, you are doing about 8.34 GPD for each of your 1000 watt lights, (16.81 divided by 2 1000 watt lights) or .00834 grams per watt day. Which will tell you what you are really getting for each watt you spend.
 
homebrewer

homebrewer

Well-Known Member
I look at grams-per-year personally. That is the ultimate measure of efficiency IMO as timing is everything. If you're working with a 60 day strain and it keeps taking you a few days to harvest/clean and a couple days to fill that area with more plants from your veg room, those extra days here and there add up and at the end of the year you've just shorted yourself an entire harvest.

Grams-per-watt is for newbs. The real test is how fast can you 'reload'?
 
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