What's your gram per watt?

[SchweeDubz]

That is doable.

Not really.

More accurate would be grams per kilowatts hours used.

It might be more accurate but it's ok to discuss both. I am asking because I've heard 1 gpm is easy to hit with LED (if the grow is setup right). I want to say I heard in growmau5 videos that he's hit over 1.5. Talking gpw is also a lot easier than grams per kw hours.

 

[GreenLogician]

I have 6 cxb3590s, four 2700k and two 3500k.
I dim them down to about 180w, and get about 1/2 oz per plant, 9 plants at a time in a 80x80cm (perpetual grow).

about 126 / 180... 0.7.
Not good, but I'm still getting used to my cobs. Nutrient issues, light burn from getting excited, maintaining warmth etc.

 

[whitebb2727]

It might be more accurate but it's ok to discuss both. I am asking because I've heard 1 gpm is easy to hit with LED (if the grow is setup right). I want to say I heard in growmau5 videos that he's hit over 1.5. Talking gpw is also a lot easier than grams per kw hours.

The only reason I say it matters depends on if you veg and flower under one light or separate areas.

If flowering under it alone the yield for a strain would be similar if it was many small plants or a couple big ones.

The difference would be veg time. You use a lot more energy and time vegging large plants.

So if you veg them 6 months and flowered then you would yield different than a 3 month veg.

 

[Rahz]

Talking gpw is also a lot easier than grams per kw hours.

I agree. They both describe electrical efficiency though, and while g/KwH does give the best indication of how efficient the grow was after the fact it's still not based on a ratio of yield to photons, or yield to radiometric energy.

 

[SchweeDubz]

I suppose I meant the light used under flowering. Moreso attempting to gauge what I can yield rather than determine how efficient my grow is. Of course it won't be completely accurate but I'm happy knowing that hitting 1 gpw with my 400w cob setup is doable. It is my goal I suppose. I think I've vegged them plenty long enough at 8 weeks.

My only concern is I'm still seeing some yellowing in some of my top leaves. Based on pictures, it seems to be potassium or magnesium deficiencies, or light burn. I can't imagine they are lacking nutrients. FFOF soil and been fed EJ w calmag. But the light is sitting about 20" above the tallest plant so I really don't know. I'll post pictures shortly.

 

[GreenLogician]

You n me both Schwee, that top yellowing!
I've turned down my lights while I keep searching for the solution. It only happens trying to blast them with light.
Whether that's light burn, or them not getting the nutes to keep up with the growth they want to do... Yet to be revealed.

 

[Rahz]

Moreso attempting to gauge what I can yield rather than determine how efficient my grow is.

Yes exactly, so you have 188-190 watts of PAR coming down, better metric for predicting the yield.

 

[SchweeDubz]

You n me both Schwee, that top yellowing!
I've turned down my lights while I keep searching for the solution. It only happens trying to blast them with light.
Whether that's light burn, or them not getting the nutes to keep up with the growth they want to do... Yet to be revealed.

Cool. I just raised my light a few inches and turned it down to about half power. My guess is light burn as most nutrient based symptoms start at the lower leaves. If it is nutrient related, I would guess a surplus before a deficiency. Last feeding they had EJ Grow, Bloom, Catalyst, Meta K, Microblast, and some Calmag. You can even see a lil bit of nute burn. Roots are coming out the smart pots like crazy though.

 

[Chip Green]

I'm pretty sure I bleached the green right out of my latest attempt at flowering with my DIY 3500k EB strip panels. The buds look pretty good to me for 7 weeks, and I had some PH issues that had to be corrected through trial and error, but I'm feeling like I should maybe keep the "lamp" a little higher for the next batch LOL...I got fooled by the lack of heat I believe.
I'm a pretty novice grower in all reality, underfeeding/ over lighting is starting to become evident.
Flowering the original gifted mother, with a pair of clones following behind every three weeks...
The 3rd set of two is looking WAY better.... LOL
Id be thrilled with .5 gpw on the first bush I created.

 

[Abiqua]

I have made this argument before and will continue to make it, with a little refinement.....gpw is strain dependent but......since most things today are a lot of muddied polyhybrids with sat/ind genes expect to gain solid yields and eventually you will probably push even some of the best limits here....

but the caveat lies on the ends of the spectrum a bit....dont expect 1.5gpw from an 18-24 week dalat sativa or from a super early finisher like Manitoba poison, guerrilla gold or something of a 7 week finisher...its great if it happens but dont expect it with certain IBL's.

 

[KonopCh]

You make GPW from lights? I always tought that my 6 Citizen COBs consumes 220W (driven at 1.05A). But when I test with kill-a-watt meter it's says 280W. So even those who swear to GPW, must include driver loss/wattage.

 

[klx]

Average or just your last yield? What is your space and which light are you using? Any other details welcome of course.

I just purchased a 400w Vero29 kit (3000k) and I'm wondering what my ball park range will be. 5 plants in my 40"x40"x78" tent. I hear hitting 1 gpw is not that hard with LED but of course there are tons of factors. These pups are 8 weeks vegging and currently in the process of going into flowering.

Edit: Just a preemptive point, I know gpw isn't necessarily the best way to measure a grow but I'm still curious. If 400g is within my realm, well, that makes me a happy man.

I use the same lights but I have more than one so there is some overlap. With blue dream I easily get 600g (~1.5gpw) from a 1m x 1m tray. With an OG on my most recent harvest I only pulled about 400g (~1gpw) on my first run with it but it is super dank and I am confident I can get that much higher now I know how she rolls.

You dont mention what strain you have there but with plants already that size you should easily hit 1g/w unless you do something wrong.

Also, I would not dim your lights if I was you, I run my lights at full power all the time and have them closer than you do and I never get burn, just some fox tailing on some strains. I have lots of air flow in my room. Crank that fucker up to full and rain down those photons!!!

 

[Lucky Luke]

@Sedan is getting 1.6gpw per sq meter with a 600w and a 400w hps.

https://www.rollitup.org/t/vert-600-400-5-plant-from-ukraine-with-love.938560/

 

[goofy81]

I get 1.3 - 1.7gpw
Roughly 6kw cxb3590 with the fastest finisher I can find, I cut at about 42-49 days 12/12.
I grow 12 plants.
I reckon 20% of my lights hit the ground too.

 

[CobKits]

^thats great for a strain that short

 

[PilouPilou]

I use the same lights but I have more than one so there is some overlap. With blue dream I easily get 600g (~1.5gpw) from a 1m x 1m tray. With an OG on my most recent harvest I only pulled about 400g (~1gpw) on my first run with it but it is super dank and I am confident I can get that much higher now I know how she rolls.

You dont mention what strain you have there but with plants already that size you should easily hit 1g/w unless you do something wrong.

Also, I would not dim your lights if I was you, I run my lights at full power all the time and have them closer than you do and I never get burn, just some fox tailing on some strains. I have lots of air flow in my room. Crank that fucker up to full and rain down those photons!!!

Hi!
Do you use the splayed heatsinks? If yes, are they very hot at 1.4A with the VERO29C? I tested them at 70W with citi1825 and they are relatively hot.. not too much but enough to let me think that at 95W it should be very hot!! thx

 

[greg nr]

You make GPW from lights? I always tought that my 6 Citizen COBs consumes 220W (driven at 1.05A). But when I test with kill-a-watt meter it's says 280W. So even those who swear to GPW, must include driver loss/wattage.

Good point, mine is based off a kill a watt meter also. Since I have a variable output driver I use it to see how much power I'm driving them at.

 

[Yodaweed]

@Sedan is getting 1.6gpw per sq meter with a 600w and a 400w hps.

https://www.rollitup.org/t/vert-600-400-5-plant-from-ukraine-with-love.938560/

His thread says 1.6 kilograms not grams

 

[CobKits]

1600g/~1100W = ~1.5 gpw

 

[Rahz]

These figures you guys are quoting are for soil or hydro? It would be interesting to see what the difference is.