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Slow growth since switching to LED

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Slow growth since switching to LED

Weedgrower 138 Replies 29,961 Views
Page 4 of 7 · Replies 61–80 of 139
#61
FriendlyFarmer90 said:
Thats really high, i suppose you supplement co2? Because if i go any higher than 28 ambient with lights on i get very larfy buds. I’m not very experienced though been growing for 3yrs now. So could be due to other issues that i was unaware of. But high temps in my tent was the reason i switched from CMH to LED. Since i started growing with the 600w zeus i have ambient 26c, leaf temp 24-25c and at night its 20c
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Nope, unless you consider the co2 that is supplemented from me breathing in my house all day :) Plants grown under LEDs seem to enjoy slightly higher room temps than plants grown under HPS. My closet plants this run have been sitting at 32c day room temps for the whole flower period and the nugs on these plants are insanely dense. I will upload a pic later when lights come on.
 
#62
N1ghtL1ght said:
A 600w HPS has a quantum efficiency of ~1.5umols per watt in comparison your LED barlight doubles that.

Then, there's 3 other major differences, the HPS light has a much better penetration or leaf transmittance and its light recipe additionally causes longer internodes and that altogether makes the plant gather more light as a whole. Also the whole plant's oxygen evolution (a direct measurement of PS2 photochemistry) will be higher.
It's because the HPS delivers a complete package of yellow/orange light complimented by very little blue, farred and much heat (IR).
In stark contrast that LED has much blue, very high red but only very little farred and no IR, all things considered creates a stocky short plant with leaves upon leaves shadowing one another. If you ever think about improving that spectrum think about a farred extension kit on a separate time that will cut down your veg-time by weeks, and give a sleep initiation, too.
But the highest priority right now I see is to dial in the temperature right. An IR heater is best because it will heat up the leaves and not the air (which is mostly vented out anyway). Or you can manage it somehow to heat up the air before the intake.
Another method oftentimes used is to blow down the air from above the LED and have both a cooling effect (= diodes more efficient) and a plant benefit. Some LED growers even reverse the airflow and vent out from below to get that effect
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Yes shade avoidance and the emerson effect. But i feel differently about the penetration and stretch being more beneficial under HPS.

Green provides great penetration and leaf transmittance and LED provides a lot lot more in that spectrum.

The stretch under HPS while having some benefit i feel as though it provides a negative to photosynthesis unless in natural sunlight because we are having to compensate intensity from a single stationary source above the plants for the tops and that means the lowers are getting far less. So while the slope of intensity fades slower under HPS (i attribute to the focus or angle of the source eg. 120 degrees under most LED and that’s only my thoughts as best as i can describe it at the moment not facts) the more compact structure under a more blue spectrum more than makes up for that and in turn imo increaseing penetration in that sense because the lower height we dont need to compensate for the intensity at the growing tips as much and overall the plant receives a higher intensity to more leaves… i hope that makes sense as its hard for me to sometimes put my thoughts into understandable text.

Add the large increase in green spectrum and i feel LED provides more penetration in a round about way.

I may be missing something and i know you may have an explanation for me so i wanted to take the opportunity for the discussion on it if you dont mind.

I also feel that IR is an iption but some newer studies have me retginking its benefit.

Also for the record if we are getting into the ravbit hole my opinion is blue leaning veg transitioned to a slightly red leaning flower followed by a very blue leaning finish. Which is where i seen tuneable LED coming more into the grow industry in the near future as we gain more knowledge in this area of all the impacts of spectral difference can make in growing
 
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#63
Shaded_One said:
Nope, unless you consider the co2 that is supplemented from me breathing in my house all day :) Plants grown under LEDs seem to enjoy slightly higher room temps than plants grown under HPS. My closet plants this run have been sitting at 32c day room temps for the whole flower period and the nugs on these plants are insanely dense. I will upload a pic later when lights come on.
Click to expand...
Ok my mind is blown, and i have been misinformed if that really is the case. I will up my temps next grow. I also do what n1ghtl1ght suggested to op and have a box fan on top blowing down with an oscilator screen, did that just because i ran out of space to put it elsewhere. My buds look pretty good (i think) but i’m still a novice compared to most people here. (My apologies if i am in any way hijacking this thread, i never really post just a lurker normally)
 

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#64
Shaded_One said:
Nope, unless you consider the co2 that is supplemented from me breathing in my house all day :) Plants grown under LEDs seem to enjoy slightly higher room temps than plants grown under HPS. My closet plants this run have been sitting at 32c day room temps for the whole flower period and the nugs on these plants are insanely dense. I will upload a pic later when lights come on.
Click to expand...
Basement by chance? Ambient co2 levels in basement are usually around 1000ppm and can be higher
 
#65
Shaded_One said:
Nope, unless you consider the co2 that is supplemented from me breathing in my house all day :) Plants grown under LEDs seem to enjoy slightly higher room temps than plants grown under HPS. My closet plants this run have been sitting at 32c day room temps for the whole flower period and the nugs on these plants are insanely dense. I will upload a pic later when lights come on.
Click to expand...
Yes they do need a higher temp the reason is as @N1ghtL1ght describes lack of IR in LED has a photomorphological effect bit also leas effect of infrared warming which causes leaf and plant temp to be lower. So we run warmer rooms temps to compensate for this
 
#67
Aqua Man said:
Yes shade avoidance and the emerson effect. But i feel differently about the penetration and stretch being more beneficial under HPS.

Green provides great penetration and leaf transmittance and LED provides a lot lot more in that spectrum.

The stretch under HPS while having some benefit i feel as though it provides a negative to photosynthesis unless in natural sunlight because we are having to compensate intensity from a single stationary source above the plants for the tops and that means the lowers are getting far less. So while the slope of intensity fades slower under HPS (i attribute to the focus or angle of the source eg. 120 degrees under most LED and that’s only my thoughts as best as i can describe it at the moment not facts) the more compact structure under a more blue spectrum more than makes up for that and in turn imo increaseing penetration in that sense because the lower height we dont need to compensate for the intensity at the growing tips as much and overall the plant receives a higher intensity to more leaves… i hope that makes sense as its hard for me to sometimes put my thoughts into understandable text.

Add the large increase in green spectrum and i feel LED provides more penetration in a round about way.

I may be missing something and i know you may have an explanation for me so i wanted to take the opportunity for the discussion on it if you dont mind.

I also feel that IR is an iption but some newer studies have me retginking its benefit.

Also for the record if we are getting into the ravbit hole my opinion is blue leaning veg transitioned to a slightly red leaning flower followed by a very blue leaning finish. Which is where i seen tuneable LED coming more into the grow industry in the near future as we gain more knowledge in this area of all the impacts of spectral difference can make in growing
Click to expand...
Too right.these lumatek lights have awesome penetration right down through the canopy.that 1000w thumper model is overkill in a 1.5 .in flower id say you will b keeping it at 30" or more easily or will fry the leaves towards the end..i do with the 600 zeus pro model at 20" only because ive ran out of height..24 " seems to b the g spot right up to 30" they are so intense.and i run full blast from begining of flower right through.and they will stretch .mine keep short till about the 7th day of flower then all of acsudden .."whoosh" they take off.im actually going to try defoliating on day one to shock them and see if it keeps them short.they dont get crazy tall its just im restricted a little in height 2.1 mtrs and you got to keep 60cm plus away...so once you add pot height and small stand your at say 40 ,they grow 1mtr -1.10 all of a sudden you are maxed out..i use tube heater lights of and a finned oil heater lights on..works great..i dont go over26.7 deg C max air temp ..thats a little over 80 and they grow pretty well around that..i havnt pushed them i guess but im still learning but getting great results..
 
#69
Aqua Man said:
Basement by chance? Ambient co2 levels in basement are usually around 1000ppm and can be higher
Click to expand...

Even better, my plants are upstairs in the bedroom across from where I sleep :) I think they get more than enough co2 for the 8-900~ umol/s I give them though. Good to see you posting @FriendlyFarmer90 don't be shy.
 
#70
Aqua Man said:
So in regards to this. Use a combination of height and power input to control the intensity and even coverage of light to the plants. You can do this any way you like the most ideal and wasteful would be to hang the light as high as possible while reaching optimal ppfd and run it at 100% it would give the most even light spread but also consume the most power.

What type of ohone do you have as you can use a free app to get an idea of how even the light spread is and some numbers to gauge roughly the intensity. Doesn’t really matter how accurate as long as it’s consistent when it comes to measurements because you are using it to ballpark and adjusting based on plant response.

What type of measuring equipment do you have eg. Lux, par, quantum meter, android phone, iphone?

All can be used easily for this purpose
Click to expand...
I have photon on my pixel pro 6. It says my ppfd is around 300 and that's not right
 
#74
Weedgrower said:
Yeah I was aiming for 500 and the only way I could see me accurately getting that number is following the bottom picture but at 50%
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Photone app for the phone is a helper as you could calibrate to the manufacturer ppfd map and be closer. It’s a 7-8 dollar upgrade to get ppfd to work for full spectrum led.

I used it for a while , but being a machinist by trade a proper guage would be best to maximize efficiency.
For the price of weed at the dispensary the 400 bucks I spent is a small price to pay to know for sure what I’m applying.

Again good luck with the grow , plants look great.
 
#75
FriendlyFarmer90 said:
Ok my mind is blown, and i have been misinformed if that really is the case. I will up my temps next grow. I also do what n1ghtl1ght suggested to op and have a box fan on top blowing down with an oscilator screen, did that just because i ran out of space to put it elsewhere. My buds look pretty good (i think) but i’m still a novice compared to most people here. (My apologies if i am in any way hijacking this thread, i never really post just a lurker normally)
Click to expand...

As promised here are some photos for proof vs words coming out of my mouth. 34c max temp, 22c is my night time temp and humidity all over the damn place 🤣

IMG 2317

IMG 2320

IMG 2321


these look larfy to you? :)
 
#76
Shaded_One said:
As promised here are some photos for proof vs words coming out of my mouth. 34c max temp, 22c is my night time temp and humidity all over the damn place 🤣

these look larfy to you? :)
Click to expand...

Hmmm. You would have to give me one so I could ummmmm inspect it more closely for larf. Yeah, that's it.
(Dude.. those are freaking beautiful!)
 
#77
Weedgrower said:
No
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Well the photone paid for LeD I believe works well. Some need to make a diffuser to use. None the less id hang at 75cm at 50% for now and see how they lookin a couple days… will give you a chance to practice new skills of reading light stress.

Meters are handy for replication but ince you can read the plants there is absolutely no need to use a meter unless trying to give a number to help another grower ir replication
 
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