Low Yield. Why?!

pulpoinspace

Well-Known Member
OP is also looking for help in identifying why the yield was low. Light wattage / output is arguable the most important factor and for all anyone knows the OP is just going based on what the person at the grow store told him. If you don't think its important to confirm wattage draw then your probably not very interested in helping OP.
yes, correct.

however, he very clearly states that his light draws 600 watts. idk how its helping him to just say his problem is he is wrong. what if hes not? there are plenty of 600w blurples out there. actual power draw is not a complicated thing, if he had the knowledge to write the actual power draw, he knows its relevant and he probably knows what it is...
 
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jjng5

Well-Known Member
I can see where your coming from dodgey, and I too have had good yields from lower temps but it is something that definitely wasn't optimal. I too know nothing about this light but 600w at the wall isnt low powered. Maybe he also had light too far away from canopy which would explain stretch....?
Of course the light was too far away, he had to have it raised up to light the entire grow space... I'm sure this killed him on that basis alone.
 

jjng5

Well-Known Member
I think the OP is mistaken on his 600w led pulling 600 watts out of the wall. If it was, he/she would have yielded a lot more in my opinion. I have a 650w led and last grow I yielded 21oz. from 3 plants in a 4x4 tent - pretty much my norm per plant.
I would also like to know his feeding schedule with the coco - I feed twice a day.
Word to big bird @ ~1g/watt -- nicely done!
 

NirvanaMesa

Well-Known Member
20" above canopy on a 600w light is not too far away. Most likely the lamp is not 600w. But the OP is missing so who cares?
 

jjng5

Well-Known Member
20" above canopy on a 600w light is not too far away. Most likely the lamp is not 600w. But the OP is missing so who cares?
At 20" I doubt it would have the foot print to cover the entire 4x4 grow. He would need it raised to at least 24" maybe 36" don't you think?
 

Dodgey99

Well-Known Member
Wow, this got angry fast :-)

I think it's fair to say, in summary.

1) OP - is your light defo drawing 600w at the wall?

Answer = yes - then your plants don't like the cold (this 100% happens with some strains), and/or your light isn't giving enough blue light spectrum (your branches are very stretchy - big gaps between bud sites.

Answer = no, then your light isn't powerful enough and/or they plants don't like the cold too.

Without confirming the light info, it's all conjecture. What we all agree on is poor lighting makes stretchy, low yield plants, and lots of plants, not all(!!), perform very badly in the cold (it is mostly about the movement of sugars in the plant slowing down - needed for growth - and eventually stalling if the cold goes on too long). There are also exceptions (and I've grown succesfully with 20 c nft res and 10 c ambient temps with one plant , but failed with another. Added a heater, and one strain started growing again, whilst the other just perma-stalled)
 

THT

Well-Known Member
, he knows its relevant and he probably knows what it is..
I read it too, overlooking something as simple as this would be foolish though.
@beepy1 should confirm without a doubt the power draw from the wall using instrumentation or just providing the light model/make might be sufficient to identify actual wattage. I do not disagree with anything you said pulpoinspace for the record.
 

Ryante55

Well-Known Member
In my 4 ft x 4 ft grow space and usimg a 600 Watt blurple LED (true power draw from outlet), i only yielded 5 ounces. I used a DNA Genetics strain called The OG #18, and I grew in coco coir. The plants remained healthy throughout the grow, but the buds never seemed to pack on much weight. The only thing that was not ideal in my grow was the temperature near the root zone, which ranged from 13C (55F) at lights off to 17C during lights on. The temperature near the canopy was from 13C (55F) to 22C (72F). Could the low temperatures cause the low yield I had? What else could cause the low yield if the plants were green and healthy looking the entire grow? I know the blurple lights are not the best but other people seem to get better yields with blurples at even lower wattage than I had. The pictures I attached show a quarter to a half of my 5 ounce disappointment.
Temps are low that was probably the major factor your canopy is also not very full... What do you want to yield? Even on a really good run I don't think you could get over a lb.
 

JayBio420

Well-Known Member
Let me try and answer this question completely for you, based on what you’ve told us.

Yield is a result of an equation that looks something like this:

General plant growth=?
(Genetic potential x plant health x vegetation time) x (Nutritional balance, density and volume + (temperature factor + humidity factor/ideal metabolic rates) + (light intensity/light distance) +(carbon dioxide and oxygen ppm) + (plant training style/branching potential factor)
________________
(Results of overfeeding + underfeeding +under or over watering +stress + insects+other damage (pH imbalances), stress or infestations) x (time the effects of the above have been experienced)

I have probably only scratched the surface of what affects a plant’s growth and subsequent flower yield, and that equation is just an approximation.


It’s a bunch of factors. Temperature is important is it impacts the RATES of chemical and biological reactions in cells of living things. A higher temperature is always better, up to the ideal cellular reaction rate. Going over ideal results in stress and increases chances of microbial overgrowth. Under temp will slow your growth, and reduce yields. This is because catalysts, proteins and even the liquids that move around and transport cellular contents are more viscous and unresponsive.

Another factor you have yet to mention, is your nutritional volume, density, nutritional balance, or the time you have allowed the plant to grow.

I have learned through experience that more soil/media is better, as it increases a plants access to many factors it needs in the above equation, decreasing the need for more veg time and limiting the potential for negative results like underwatering, under feeding and the other factors in the denominator of the equation.

Use more soil, time and light
Intensity, and produce more bud sites, and remember if you aren’t comfortable naked in the room, your plants might not be either.
 
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growingforfun

Well-Known Member
I think your showing your age old timer. "Wink" us new members dont show respect when none is given. Is this how you greet all new members. Everybody else i have spoke to have been courteous and just generally trying to help people. And don't get your panties in a twist, I'm just stirring up an old boy. (That grows in frozen water)
To be clear your the one who started ALL OF THIS. you do realize that right? Hahahahaha but keep holding on to your claim it's the temps, the thread has moved on.
 

HydroRed

Well-Known Member
yes, correct.

however, he very clearly states that his light draws 600 watts. idk how its helping him to just say his problem is he is wrong. what if hes not? there are plenty of 600w blurples out there. actual power draw is not a complicated thing, if he had the knowledge to write the actual power draw, he knows its relevant and he probably knows what it is...
In @THT defense, Ive seen more people than not on RIU that claim and really believe they have a 600W blurple light drawing 600W from the wall when in reality its more like 140-180 from the wall. I was hoping the OP would chime in with a make/model to shut us all up haha
 

beepy1

Member
In @THT defense, Ive seen more people than not on RIU that claim and really believe they have a 600W blurple light drawing 600W from the wall when in reality its more like 140-180 from the wall. I was hoping the OP would chime in with a make/model to shut us all up haha
I am using a viparapectra v1200, with claimed 524 watt draw. I also added a 75 watt RapidLED COB fixture.
 

pulpoinspace

Well-Known Member
to me in the pics your plants look quite happy just stretched like crazy. makes sense lower buds couldn't fill out cause canopy was so uneven. more LST, and maybe more/closer light if you notice plants stretching. during veg or early flower.

people will be along to tell you that because blurple LED is less efficient you want closer to 50w per square foot, ~800w for 4x4. TBH rather than adding another 200-300 watts of blurple, since you have low temps anyway my recommendation is to get a cheap 1000w dimmable HPS system, the tried and true which has proven to work in a 4x4. buying more blurple doesn't seem like a good idea, and high efficiency LED will be a substantial investment, and youd still have low temps.
 

beepy1

Member
I've also got a lemon og kush plant 7 weeks into flower. (Half lemon skunk and half og #18.) As far as i know the og #18 is sativa dominant. My lemon og looks to be only half way through flower and seems to be a nearly 100% sativa pheno! I presume this is from the og #18?? Maybe your og #18s were harvested a little early also??
Yeah, they were harvested at 70 days from the time i switched to 12/12, but most of the plants still had about 50% clear trichomes. I noticed quite a few hermaphrodites/stamens/nanners at day 63 and I didn't want to end up with a bunch of seeds so I chopped them a little earlier than I would have liked. Most buds didn't seem to be increasing in size after day 60 or so, but a bunch of buds started foxtailing around that time.
 

PURPLEB3RRYKUSH

Well-Known Member
It was 600 Watts from the wall. I measured this with a power meter to confirm that the manufacturer was giving me the correct value. I also measured the light at 22 inches above the tops of the plants. I didn't have a flat canopy though so many bud sites were further than 22" from the light.
Well if its 600 watts at wall u should be pulling atleast a pound
 
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