Is talking about grams per watts absolutely rediculous?

[Shcrews]

and those kilowatt hours should include ventilation, a/c, pumps etc, no?

yes definitely. a useful and simple measurement of indoor gardening productivity is Weight Harvested / Total Electricity Used. However this does not take into account the length of time it takes to complete a grow. that requires a more complex formula.

 

[Snype]

You can give most growers as much VEG time as you want and they still can't get a gram per watt. That says something. Getting a gram per watt in any amount of time is a great judge of something valid. The growers who can get it with less than a month veg is even more great.

These calculations are just calculations that we make up. The equation can be whatever you want it to be to judge the yield output of your grow. If you want to add time to your equation then go for it. There really is no standard. It all matters of what you are going to say is your flowering and VEG times as the standard and then add all your watts that you are using for a given space.

Some growers might have a 57 day strain or a 65 day strain or a 70 day strain. You would have to have a standard for these equations that makes it very difficult for people to agree on.

I would think the standard would be flowering times of somewhere between 65-70 days. I'd probably go with 70 as the standard, if there was one.

Then I would think VEG times would be added to the equation an all the electric that you use for the grow. It's never really going to make sense because some growers are growing in very cold climates and some in very hot climates. I don't think any equation can really be accurate to compare all growers in.

In reality, it's not like most growers get a gram per watt if you only include the light and don't include VEG time anyway. So those calculations are more in your favor to get a gram per watt and 90% of growers don't get those numbers. That's pretty much why just counting a gram per watt with your lights and not calculating VEG times seems like a good standard already.

Now if you are already getting a gram per watt, then I can see why it's time to change the equation and add in the other variables but until you get there, it's pointless.

 

[PetFlora]

There are simply too many variables, but a good light barometer is umols/meter^/sec

Lets say ideal is ~ 40 umols/m^/sec, then the difference can be directed at how close to ideal the growers lights are.

But that is only one factor. RH, ambient temps, control of PPMs & pH... are also important to hitting the desired number

 

[CanniDo Cowboy]

Grams per watt may not be "absolutely ridiculous" but IMO, it certainly cant be used as an absolute or exact standard. How can it be when:

1) In the interest of supply and demand, market values can vary from region to region and as important, at what time of season the product is marketed, thereby directly disrupting any grams per watt consistency

2) The simple fact that yield weight can vary from strain to strain depending on whether it has Indica traits, Sativa traits or both, not to mention running multiple strains at the same time, which would render grams per watt non-applicable if not impossible to determine

3) Regional location can dictate use of additional electrical use: room climate control hardware such as humidifiers (dry climate), de-humidifiers -(tropical climate), heating (colder climate), cooling (hotter climate) etc

4) The indoor grow space itself, depending on size (smaller/larger) can require a more complex air environment management program which usually results in increased electrical usage while space location, such as a basement/attic/out building, may require the same.

Finally, I'm not sure where man-hours fits into the grams per watt thing. Are you hand watering 50 plants or using a more man-hours reducing drip system? In this game, time is also money but as most of us know, that little production overhead inclusion quickly goes out the air filtration system, assuming you can afford to run one...lol CC

 

[Baked Alaskan]

Its been stated before but you need a time period "grams per watt per 30 days". This is still not perfect.

Most ancillary electric usage per 1000 watt light is fairly average, especially in your own grow area, that is why it works across the boards. Again this is not perfect but over years of data you get a general idea where you are every month (week, day, hour).

This way of measurement is best to check against yourself. Against others I wouldn't know, or care, how to get an average.

Remember its useless unless you have a time period. Hope this helps a bit.

 

[Baked Alaskan]

For a while I was pulling .35 gpw per month, nice consistent good smoke.