[Superauto]

How do you calculate the gram per watt, what is the right formula?

Do you just take the dry weight and divide it with the lamp wattage?


What about alk the variations here?
I mean, running 12/12 from start and growing autoflowers running 24/0. Can it compare?
What about how many days you have been growing.
There are a big difference in 90 days autoflower and 6 months photos.


Do you divide the grams to the actual kilowatt hours spent on the entire grow from A to Z?

[Ibechillin]

Dry weight from harvest divided by the amount of watts used by the lights during the flowering cycle only for that harvest.

Usally GPW is shared as how much one lamp produced over a given area beneath it like 1000 watt hps over 5x5 area yielded 2.23lb = 1000 grams for 1GPW.

In vertical gardens you can have multiple light sources hitting the same plants in an area. Like 2 600 watt hps lights hung vertically on top of eachother surrounded by a donut of plants yields 4lbs = 1792 grams for 1.49 GPW.

[Guy Brush]

Gpw is just a guide line to see how much you are making progress. If you really want to compare to other peoples grows you have to provide information about area size and veg time duration.