Tried lighting variety; led, 315lec

[Farmall]

Does anyone think that leds are too strong once you get over 500w. I’m using 2 1000w units over 6 hydro individual buckets. They are now 24” away as the taller they get, the harder it is to keep distance. The sawtooth edges of leaves are slightly curled up, discovered a text book image of leaf burn on a few leaves tonight where the edges and tips are almost bleached yellow. They are in transition about day6 at the new lighting period 12/12. The lanky growth has 6-7inches between node and they are stretched.

On the other hand, the 315LEC with 3200k bulb is over the 4 huge and dense soil grow. Had a 3rd 1000w led and I’m using it as a slightly angled side light. These girls just look like premium models of the ideal plant. Also an 12/12, I may be seeing the development of silvery bud tops emerging under the broader spectrum light. Their stems are nearly 1” wide at the soil level and at the 3’ Level, over pencil thickness. Since it dark right not I can’t get a picture until tomorrow but I’ll post s few for comparison.

so again....are these 1000w led too much to use with 8’ ceilings and the plants 1 foot off the floor for ease of water draining with hydro nute changes. In a tent it would be even closer quarters and I would have reached a limit by now. I am letting these all go thru a complete grow to see how the issues I’ve had will effect the outcome compared to the soil and 315 lec lights and again, I’ll report back

[DrPhoton]

Your talking about equivalent wattages which is not valuable and referencable data to use. Stick with actual wattage at the wall for future references.

Many LEDs emit their light over a small surface area with very narrow angle lenses. This means it generally requires a larger proximity between the light fixture and the plant canopy. Gas discharge such as that using reflectors, typically have a larger surface area and angle emission that allows the fixture to be closer.

This has nothing to do with efficiency, as most economical or budget fixtures are not more efficient than gas discharge.

[Farmall]

Thank you Dr. Photon, I have read a few of your amazing articles but obviously something failed to sink in. Later today I will go back and make a more viable comparison. If you have an opportunity tomorrow, I will get these photos up and ask if you might see evidence of lighting problems or some other thing an experienced person could know. Very much appreciated.

it starts out as a little thing...but after 3 months, it changes to a deeper level of enjoyment, love and protection of the energies spent getting to this level... those and every future step in the process must be done well or ...you’re out and alll that is out the window.... ouch

[DrPhoton]

Il be happy to have a look. Yes its certainly a entertaining and challenging job.

[Farmall]

The first group is the soil under the 3200k 315LEC lamps using the cloud line t6 exhaust fan

[DrPhoton]

They looking pretty good. Nice thick stems on those soil plants.

Whats the size of the grow area they are in ?

What is the power usage of those LEDs ?

Have you got much room left to raise the lights for the last week or two of the flower stretch ?

[Farmall]

This is a 10x10’ room, no windows in a warehouse. Temps are consistent 74, humidity was 60-63% now dropped down the last 3 days to 57%. I used that Mylar stuff to cover the walls as they were only 10’ Long.
as for light stretch....soil...yes. On the hydro, whew it’s going to be close. I will have about 15” over what you saw there. I also have a 1000w HPS air cooled light setup with dimmable ballast at 50% 75% and 100%. Which I thought about switch to but I’m not sure if I was “allowed” to tie the two lights to the same exhaust system. Exhausted air is current 74 degrees from the 315 LEC.

[Farmall]

Oops... the power consumption says 284 watts...for each LED unit

[DrPhoton]

So yea, as previously said LEDs are typically harder to work with when dealing with height issues as they are designed to focus their light more, compared to traditional light sources. This has the benefit of improved efficiency by limiting the amount of radiating losses. But will have inferior uniformity, with light concentrating in the center of the footprint. As i also said, the equivalent wattage is not accurate, never is. Those two LEDs combined, at best, equivalent to a 600wHPS. Though because you are not running a complete enclosed grow system (reflective walls all around and the canopy filled), LEDs are beneficial in these circumstances.

If you run into height issues and you can dim your 1000w HPS enough that gains you a little more headroom, then this will be a good plan B if this does get out of control. You can definitly link hoods together, which can be either in series or parallel. As long as the exhaust system can sufficiently provide enough airflow to vent the heat. I would guess it would. Its not a large volume of air, it just needs a high enough torque to pressurize both hoods (assuming they are sealed).

Another solution to height issues is supercropping (scropping) which can help reduce the height of the plants in situations such as this, these techniques can be applied in flower with minimal negative responses.

You may also want to think about lollipopping. You can get away with light pruning in the first week of flower, but i am always hesitant doing anything after two weeks. As the plant will be working on flower devlopment and stress at this time can be damaging. Though many people still do it.

[Farmall]

Well, thank you for taking the time to review this for me. So apparently switching the type of lighting will not be an issue. I can easily route the 6” venting through the second fixture and have both bulbs for the 1000w fixture Metal Halide and High Pressure Sodium. The progress in the last week of 12/12 lighting seems to have created a tipping point where on THIS particular crop, it will stay as it is until harvested. Having some nice colas with some certainty beats the possibility of losing all of them. There always next time, or so I assume.

I might gain an additional 9” by taking the 5 gallon buckets off of their table in addition to the lamp changes with an overall gain of near 24”.

while I have read and read about these cropping techniques and seen quiet a few videos, I still hesitated in cutting down such cool looking growth mostly because I was a little afraid of ruining the overal attempt. I did top them and probably should have kept topping the newest growth as it occurred but, I did not know you could do that until last week when I learned it in a cultivation video from Green Flower.

ironically, I have also recently read many of your published lighting articles and it gets tough to remember so many things, so new to me, and all being thrown at me in a relatively short time. Additionally, I move to do things a bit sooner than my skill may dictate. READ THESE INSTRUCTIONS !...” really ?” On the other hand, I have been pretty lucky with a few things because of that.

Have you or do you know whether or not it is beneficial to rotate the soil pots 90 degrees of so every few days in order to expose the plant to lighting differences?

[DrPhoton]

Yes it can be overwhelming all this mumbo jumbo that you have to remember, which is why i dont mind answering questions.

Rotating the plants can help provide uniform growth patterns if light is not uniform. I use many plants and shift them around to obtain a uniform canopy. Short plants are sent to the middle and taller plants vice versa. So it can help.

You shout if you need any more help.