Grams Per Watt

[Flockshot]

Claims make by light manufacturers and sponsored growers no longer impress me, and I discard them all.

I only care about "grams per watt" in various growing conditions.

For the record, I use 400w T5 for early veg, 600w MH for late veg and 600w HPS for flower, and get .67 grams per watt (407/600) on my last grow of photo in coco, chemical nutrients/white widow.

Additionally, I am a grower with limited experience who has not, as of yet, had a "seed to harvest" trouble-free grow

Hopefully, that helps you understand what you can expect based on your growing method, if you choose 600w MH/HPS as your light.

I would like to hear what you think I should expect from your lighting choice.

[D.A.A.S.69]

Morning Flockshot, that's a great question your asking, and I can't wait to hear the answers.
I just started using my new light after my autoflower was already about 40 days old, so i ain't got a clue what to expect, it's a 315cmh.
As for your 400watt -600watt light,
.67 grams per watt , ain't that about what it's supposed to do, or maybe even a little better.
like I said ,I ain't got a clue, but I can't wait to hear the answers, until last year I have always used just the Sun on our grows.

[Flockshot]

I am not disappointed, but I know I can do better if I learn more about what the community is actually accomplishing.

[Sammy]

315 LEC , averaging about 14 oz per Harvest. 14*28=392÷315=1.244 g per watt. Substantially better than my 400 HPS was doing. I think the math is right ☮️

[Flockshot]

That is a very intriguing. Well over a gram per watt is twice what I am getting now. I got 407 out off 600 watts and you got 392 out of 315 watts. So what is the rest of your setup information? Coco, dwc?

[Sammy]

CYCO coco, CYCO nutes,3 gallon smart pots average vegging times about 2 months, however I'm vegging one quite a bit longer this time going to go for a pound out of one plant ☮️

[Doubledealing72]

I finished out my first grow a little over a month ago. I used 3 55w autocobs over 4 plants, and ended up with 7.57 oz, so g/w was 1.28. if you're curious about them I'd be happy to talk about them.

[Flockshot]

An other result well over a gram per watt. Tell us more about your methods.

[Doubledealing72]

Autocobs rock. Super efficient, completely silent, plug n play, very minimal heat given off. My first grow came with many problems along the way, so needless to say it could have been more. These things rock though, my electric bill only went up $20/month compared to not growing at all.

[DW2]

Howdy Flockshot, My growing setup is DWC with eight 55 watt CFLs, four at 2700° K and four at 5000° K. My last grow yielded 246.4 g of bud and 397.3 g of trim (with I use). Counting only the bud, My gram/watt yield was .56 g/w, and including the trim was .903 g/w.

[Flockshot]

CFL's continue to be a valuable and effective tool for many types of grows. You are within .1 g/oz with my 600w HPS and you burned a lot less electricity than I did.

[DW2]

Flockshot, The only draw back with the CFLs and lower wattage is that it seems to take me more time to mature and the buds have been (or appear to be) less dense than others have grown. On the 'good side' of less dense buds, they dry out faster and I have not (knock-on-wood) had any problems with bud rot, so far. I am planning to build two new lamps, either with the same bulbs and make them 330 watts, or go to smaller (23 watt CFLs) and get 20 in the same space for a total of 360 watts. The 23 watt lamps are more readily available and may cost less over all. The 55 watt bulbs cost around $12 to $15 each (and then add shipping!).

[abadtrip]

on my first grow with a 315 cmh I got .88gpw i hope to kill that on my wonder woman scrog I have going right now.
with my 300w led 136 tire watts I got .84gpw
I am very happy with my numbers I hope to push my 315cmh numbers too the 1gpw range.

[Flockshot]

Impressive numbers to be sure. I hope to get to that level soon. The CMH seems right in line with the LED in this case.

[D.A.A.S.69]

My first grow with using a LED light with a 145watts at the wall along with 5, hundred watt equivalent cfls I got i cant remember very well, but well over a gram a watt, but i used lots of LST ,and had a flat tabletop canopy.
Plus I had a plant that might have been a fluke, cause she wasn't supposed to get that large I don't think, she was a Northern Lights auto from Nirvana, and I've still got 5 full jars of bud left from about 3 months ago.
ps- plus we do lots of burning around here. We ain't been trying to save any for sure.

[Flockshot]

That is top notch growing. I didn't expect this many people to be getting over a gram per watt. I have a long ways to go.

[Flockshot]

I am amazed at the number of people who are getting over a gram per watt.

[D.A.A.S.69]

I believe the reason i did pretty good was because of the plant training, plus I don't believe I grew a normal plant, I believe she was larger than she was supposed to be for an auto, but I ain't sure.
I know I can't wait to use my 315 from start to finish though, just to see what it will do.

[GreenDragonRon]

I did really poorly my first grow, just over 0.5 g/W. I think I over did the N during flower and none of my buds really swelled. During harvest, I only dried and cured the best buds, I threw plenty of smokable buds into my hash stash. Not really a big deal for me as I can't smoke or vape, I made plenty of MCT and coconut oil to keep me medicated.

[Flockshot]

I don't consider .5 gpw as doing poorly at all. I consider that as someone who knows what they are doing.

I don't know how growers are beating 1 gram per watt by 25%, but they should write a book. Nobody I know can do that. As a matter of fact, there is an article on this site about how to get to 1 gpw, let alone 1 1/4 gpw.

http://www.growweedeasy.com/1-gram-per-watt

[Franklin]

It always seems to me that gram per watt needs one more variable to really be interpretable: days. Doing 1.0 GPW in 90 days from seed would be far more impressive than 180 days from seed, as it would cost half as much electricity.

[Flockshot]

I am not prepared to start paying 3 dollars per watt for a light that will probably be obsolete in 2 years. It's just too rich for my blood.

[Doubledealing72]

If you're referring to the upfront cost, it more than pays itself off within the first harvest based on electricity cost. Running 4 only increases my bill $20. My buddies electric bill was ridiculous when he was growing with HPS. However, he was growing a few more plants than me lol.

All that said, I understand you aren't interested in them, so I will stop talking about them. Hope you find the light that is right for you!

[tyler_ hobbyist]

Leds are amazing lights but u dnt get the same yeild as hps but u can buy cheap leds for under 300bucks I use bestva leds and a freind of mine uses vipraspectra and we both get amazing results the only issue with leds is there watts arnt true there a gimic for sales u need to find the true watts of the light my 1000w bestva actualy only draws 200watts from the wall. That needs to be takein into account. Plus leds are like lazer beams 90percent of there usuable energy only gets pointed down so u need a lot more lights for a coverage area. But u are right ur energy cost is lower but the cost per light is a lot more watt per watt. I use 200,350w leds for 1 plant and it could use more even when I keep my light at 4-5inchs away. Just some thoughts

[tvbfe]

Genetics play a huge part in yields

[Flockshot]

Absolutely. I agree. That is why I indicated in my post that I had grown White Widow to get my numbers.

If I grow something like Wonder Woman that is noted for huge yields, I would expect to increase my grams per watt number, but not my skill as a grower.

[tvbfe]

Right on

[Blazed227]

Ok so im running 7 girls under a 315 an a 630, no idea what it's gonna yeild, previously with the 600 watt hps I was runnin, I think I got 7 ounces outta 6 plants, but also had alot of problems with heat stress from the lights an almost froze them when I hooked up my new fan so it wasn't to bad I guess lol an this last grow from 2 medium sized plants an 2 small small plants I yeilded like 6.5 also with the hps, the 7 that are going now have had the cmhs the whole time flowering so I'm excited to see how they turn out also since they haven't had any problems thus far (knock on wood) hopin for a good bit more this time.. buds have always been really airy an light.. hoping this will change now that I got more light in there

[D.A.A.S.69]

Morning 227, with your new lights, and the way you train your plants , with no problems, l don't think you will have any problems at all getting great results.

[Blazed227]

I hope your right!! Thinking of converting my tent into top fed Dec.. an see how that turns out..

[abadtrip]

So now u got me doing math thanks I love it.

so I am going to use my pineapple express for this examle.

dry weight 105 grams
light 300 w led 136 w at the wall on for 62 days 24 hrs a day 1488hrs
136 x 1488 = 202 363 ÷ 1000 = 202.363 k watts of energy used

105 ÷ 202 = .52 grams per kilowatt hr

Energy cost 17 cents a kwhr

202 x 17 = 3434 ÷ 100 = 35 dollars for 105 grams of some of the best weed I have Eva smoked.

let me know if my math is off

[Flockshot]

Heck no, I ain't checking all that, but thank you for the complete picture. This is information that serious growers should know about their own setup.

[abadtrip]

This only accounts for the light I have an exhaust fan a circulation fan and air pump that needs to go into that calculation to get a tru picture of what is really costs.

[Flockshot]

I agree.

[Obi-Wan]

Ok, I started growing in February of this year and I have harvested 5 times. Here are my results in order of harvest with multiple light variations over that time. All plants were grown in Coco with GH Trio nutrients and gpw is calculated using true wattage.

1st harvest-3 Auto-flower plants, 2-60 day Wonder and 1 Cheese. 56.4 grams using 2-300w GalaxyHydro led= .20 gpw.

2nd harvest- 4 photoperiod clones, 3 Girl Scout Cookie, 1 Cannatonic. 84.6 grams using 2-400w Roleadro COB = .21 gpw.

3rd harvest-1 GSC, 1 Cannatonic, 1 OG Kush. 280 grams using 1-600w Viparspectra and 2-300w GalaxyHydro = .51 gpw.

4th harvest-1 GSC and 1 OG Kush. 253.5 grams using 600w viparspectra/veg switch only for veg and 2-400w COB for flower= .63 gpw.

5th harvest-3 Snow White. 282.2 grams using 600w viparspectra/veg switch only for veg and 3-300w led for flower = .69 gpw.

My sixth grow grow is in week 6 of flower under 3-300w leds. 1 OG Kush and 1 Snow White, each in 5 gal. Bubble buckets with a 5 gal. reservoir outside the tent. I’m hoping to get to .75 gpw for this grow.

When end I first started growing I thought more plants under more light would get me better yields. I have since learned fewer plants with the right amount of light filling my canopy gives me the best results. I just pulled the trigger on a 315 cmh that I will be using for my next grow. I’m hoping to pull the same or more yield at 90 fewer watts.

[Flockshot]

You can just see the learning curve. Every new grower should see these results and the continuous improvement.

[Sheesh]

Last harvest was coco with topping, LST and Scrog. 291g includes 45g of popcorn buds. My light is a California Light Works SS440 LED with 320w at the wall in bloom mode. .9 gpw if including the popcorn bud. .76 gpw. Of course, half the grow was in veg mode at 220w at the wall. And, I have room for one more plant, so I could add another 110 g or so if I wanted to manage 4 photos instead of 4. So, lots of variables for sure.

[Flockshot]

I would go with the .9. By the time they get used, all those popcorn buds will be good to have. Exceptional results.