Grams per watt what is the maximum that can be obtained?

Using 2 x 600 HPS have never felt have reached maximum grams per watt for the area.
Light is kept in by using roller blinds as curtains and mylar on the ends
Area is 8 foot by 5 foot with 40 plants gives each plant a sq foot.
Changing to LED found 4 x 120 watt panels are about equivalent so that's what I went with.
35 days into flower more than happy with how these lights are performing
2.5 grams per watt? Maybe. Worked out like this app 800 flowering heads @ 1.75 grams dry average.
your thoughts?

The whole grams per watt thing is a total farse, other than that, if you want to maximize output in a controlled environment, and you are not using all the tools at your disposal, (ie; Co2, UV), then getting everything else, (temp, RH, nutrient ratios, lighting and airflow) dialed-in, is ultra important. And just from your picture I can see you don't have all those things dialed in. For example, when running led(s), samsung tech, using more didoes running at a max of 70% of their rated output will always outperform using less didoes at there max rated output. And in your picture, I can clearly see you don't have enough light in there to maximize your output, (ie; there are to many shaded areas) And it takes 6 x 288/120watts boards running at 480watts, (their max efficiency) to equal one 600w HPS, not 4 x 288/120watts boards running at 320watts, (their max efficiency)!

I concur you need to be running about 1600w at the wall of top bin leds in that space also agree gpw is horse shit some companies claiming x amount of gpw is utter bollox I’m chuffed to fuck if I get 1gpw using hps

GPW is basically meaningless!

I can shatter GPW #'s with SOG...
Small HID's in 2x2 area's - 1088 grams - 4.325 gpw
34 plants
32 g average yield
250w HID (1K watt equivalent to a 1K in a 4x4)
ebb table built for dialing in large tables.
Hesi Nutes
Dr Geenthumb G13 strain
This took a cpl of runs to square away the over 4.

NO reason that couldn't be done with LED's either.

The problem? Plant counts!

A 4x4 with 64 plants in Plant Warrior 1 gallon pots - To close to plant limit to be a rotational run.

Dr. Who said:

GPW is basically meaningless!

I can shatter GPW #'s with SOG...
Small HID's in 2x2 area's - 1088 grams - 4.325 gpw
34 plants
32 g average yield
250w HID (1K watt equivalent to a 1K in a 4x4)
ebb table built for dialing in large tables.
Hesi Nutes
Dr Geenthumb G13 strain
This took a cpl of runs to square away the over 4.

NO reason that couldn't be done with LED's either.

The problem? Plant counts!

A 4x4 with 64 plants in Plant Warrior 1 gallon pots - To close to plant limit to be a rotational run.

Click to expand...

Thats OK cos you still have a GPW
your figure is what i was thinking is a good possible figure and maybe a little more maybe 4.5
I roasted the roots on this grow had to veg for a extra month to bring the roots back and it stunted them so I know there's a lot better to come
what's the problem plant counts?

harrythehat said:

Thats OK cos you still have a GPW
your figure is what i was thinking is a good possible figure and maybe a little more maybe 4.5
I roasted the roots on this grow had to veg for a extra month to bring the roots back and it stunted them so I know there's a lot better to come
what's the problem plant counts?

Click to expand...

State limit is 6 for you and 6 for each patient - up to 5 patients.

So SOG isn't the right choice. I run perpetual harvest operations. This makes up for the other. Optimal control of all environmental conditions, Complete dial in's for the strains and keep it consistent!

Beating that 4.325 will be next to impossible.. Not saying it couldn't be done but, that was a lot of work and trying. Just to get to that point. Space limits and light intensity for the space are one key.
The right strain used is another.

As far as you doing that with a few plants and a space. NOT going to happen!
Sea Of Green kills single plant possibilities.

SCROG gets closer but, still can't beat SOG....

I also do not do any hydro any more.

Im pretty sure all the grams per watt is best.

Gpw is led advertising, here's Mars hydro -


300w at 2.5g/w = 750grams max.

I'll let everyone else discuss the logic of that figure.

Dr. Who said:

State limit is 6 for you and 6 for each patient - up to 5 patients.

So SOG isn't the right choice. I run perpetual harvest operations. This makes up for the other. Optimal control of all environmental conditions, Complete dial in's for the strains and keep it consistent!

Beating that 4.325 will be next to impossible.. Not saying it couldn't be done but, that was a lot of work and trying. Just to get to that point. Space limits and light intensity for the space are one key.
The right strain used is another.

As far as you doing that with a few plants and a space. NOT going to happen!
Sea Of Green kills single plant possibilities.

SCROG gets closer but, still can't beat SOG....

I also do not do any hydro any more.

Click to expand...

Thank you now i understand am UK so does not apply still closed doors and illegal

With a 60 days veg under a 1000w Hortilux HPS, 20 gallons Promix BX, and an old Barneys Farm G13 x Haze clone I can get 30oz. I also bend the plant over from an early age, and no topping.

Do you mean you only have 4x120w panels ?

Brettman said:

Do you mean you only have 4x120w panels ?

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Yes have a look in the picture 4 x 120 watt generic Chinese panels. Am freakin astounded to what there producing and its a grow which I made a severe cock up burning the roots
even better next time LOL

it might look ok now but you will be disappointed with the flower in the end. I guarantee it lol. Your at like 15w. You should have 8-10 of the panels.

Edit: I thought you had an 8x4 not 8x5. So you have like 12watts lmao. You need 6 more of those panels. It will be like when I started with blurples, they kill it in veg but can not produce dense flowers.

Brettman said:

Edit: I thought you had an 8x4 not 8x5. So you have like 12watts lmao. You need 6 more of those panels. It will be like when I started with blurples, they kill it in veg but can not produce dense flowers.

Click to expand...

to the curtains its 5 foot. 4 foot to centres of plants. Yes 12 watts per plant. To me its doing pretty much the same as HPS at the mo. Only they look a lot better.
will carry on the experiment to the end its in grow journals. winter solstice flip if you want to view it later