LED dimmable lighting and watts

Palgravefarmer · Jan 17, 2021

Hi All,

Being a newbie to LED lighting with the dimmable function, I have a dumb question albeit an important one:

If (to the wall) I have a LED light at 100% power of 700 watts, should I dim it to 50%, would that mean I am now running 350 watts instead of the 700W?

Also, if I have an overkill LED light in a 4x4, can I run from seed to harvest at 50% dimmable should it meet the ppfd requirements?

Many thanks in advance.

coherent · Jan 17, 2021

When you adjust the dimmer on an LED light, your power usage goes up or down directly proportional to the wattage you've selected. To put it simply, if you dim your LED lights 50% they use about 50% as much energy! So, if your light is overkill, you would save money lowering the light and dimming it vs raising it and increasing brightness as long as your coverage is still sufficient.

gorillaglueaaron · Jan 17, 2021

Palgravefarmer said:
Hi All,

Being a newbie to LED lighting with the dimmable function, I have a dumb question albeit an important one:

If (to the wall) I have a LED light at 100% power of 700 watts, should I dim it to 50%, would that mean I am now running 350 watts instead of the 700W?

Also, if I have an overkill LED light in a 4x4, can I run from seed to harvest at 50% dimmable should it meet the ppfd requirements?

Many thanks in advance.

Depends on the potentiometer that's being used. Most that are used for LEDs are linear but some are quadratic. Short answer most likely 700w at 50% is 350w.

Second question, I don't know which light it is so I can't really help you with that.

gorillaglueaaron · Jan 17, 2021

coherent said:
When you adjust the dimmer on an LED light, your power usage goes up or down directly proportional to the wattage you've selected. To put it simply, if you dim your LED lights 50% they use about 50% as much energy! So, if your light is overkill, you would save money lowering the light and dimming it vs raising it and increasing brightness as long as your coverage is still sufficient.

That's a good point. The higher you raise the light, the better the coverage is so you can decide whether you want better intensity or lower electricity cost.

Dub_City405 · Jan 17, 2021

Run the light how you want. I suggest 100 percent in flower. I suggest no lower than 50% during seedling and veg. Id really go to 100 week 2 of veg. I want 4 to 5 ft plants. Bigger weight.

growsince79 · Jan 17, 2021

Dub_City405 said:
Run the light how you want. I suggest 100 percent in flower. I suggest no lower than 50% during seedling and veg. Id really go to 100 week 2 of veg. I want 4 to 5 ft plants. Bigger weight.

I've found 5 foot plants indoors are a waste of time and money. Why grow em that extra month just to cut the worthless bottom 2-3 feet off? My best relative yields comes from fairly short plants with 3-4 week veg.

gorillaglueaaron · Jan 17, 2021

growsince79 said:
I've found 5 foot plants indoors are a waste of time and money. Why grow em that extra month just to cut the worthless bottom 2-3 feet off? My best relative yields comes from fairly short plants with 3-4 week veg.

Do you find quality even slightly worse with smaller plants?

growsince79 · Jan 17, 2021

gorillaglueaaron said:
Do you find quality even slightly worse with smaller plants?

It's always the exact same terps and potency as if I grow it 6 months.

Dub_City405 · Jan 17, 2021

I only veg for 3 weeks then flower for 8 weeks. Water 9th week and cut and dry. Idk if a harvest every 12 weeks is bad or not.?

gorillaglueaaron · Jan 17, 2021

Dub_City405 said:
I only veg for 3 weeks then flower for 8 weeks. Water 9th week and cut and dry. Idk if a harvest every 12 weeks is bad or not.?

Just depends on your grow style.

growsince79 · Jan 17, 2021

Dub_City405 said:
I only veg for 3 weeks then flower for 8 weeks. Water 9th week and cut and dry. Idk if a harvest every 12 weeks is bad or not.?

5 feet tall with a 3 week veg from seed sprout? What strain was that?

PK1 · Jan 17, 2021

Dub_City405 said:
I only veg for 3 weeks then flower for 8 weeks. Water 9th week and cut and dry. Idk if a harvest every 12 weeks is bad or not.?

what do you yield? and i take thats photos only?>

Dub_City405 · Jan 17, 2021

Why would i use seeds if i got clones? Only youre talking about seeds

growsince79 · Jan 17, 2021

Well that makes more sense. How tall are they when you flip to 12-12?

Dub_City405 · Jan 17, 2021

Lol its the only sense when im talking about that quick flip time. Usually 2 ft. Or 3

growsince79 · Jan 17, 2021

Dub_City405 said:
Lol its the only sense when im talking about that quick flip time. Usually 2 ft. Or 3

Have you tried flipping sooner like a sea of green. 3-4 clones/sqft - 1 week veg? No wasted time or vertical space. Probably get a better relative yield and easier trimming.

Aqua Man · Jan 17, 2021

This again is an example of different grows and experiences being over simplified and that can lead to issues. If you want to take the simple route then that's what ya get. No different than say teaching math... you ask whats 2+2 I tell you 4 it does you no good when you want to know what 5+5 is. If you learn addition then you can answer yourself in all scenarios

First advice is to read your plants and learn the symptoms of too much light. This will change in every single grow room, each strain and has many contributing factors. So IMO you cannot just go with arbitrary 50% 75% 100% numbers.

DLI (daily light integral) is where you want to start and things will start making more sense. DLI is simply the amount of photons (light energy) a plant receives over a period of..... a day. It clear when you have a longer light period you need less light to achieve the same value than with a shorter light period like photos in flower.

Going against my own advice and giving a simple answer is if you are running 18/6 and change to 12/12 you will need to increase the intensity by 1/3 in order to get the plant the same amount of light per day. This is why in flower we need more light.

Another eg. Is 24/0 light to 12/12 you need to double the amount of light. But 24/0 would require less light than 18/6.

You also need to take into account the photosynthetic rates because plants can only use so much light at a time. This is where you need to learn the symptoms of too much light.

If you want I can dig up some articles but you can simply google DLI cannabis and light stress symptoms cannabis and ask questions that arise from your reading.

The hardest part of learning is not knowing what you dont know. So there are 2 things you can take time to learn about to help answer your own question and understand in the future how you may want to adjust your intensity and photoperiod.

If you have questions on it just post back but nobody can learn it for you and it's no good having an answer if you don't understand it.

Dothraki · Oct 25, 2021

Aqua Man said:
This again is an example of different grows and experiences being over simplified and that can lead to issues. If you want to take the simple route then that's what ya get. No different than say teaching math... you ask whats 2+2 I tell you 4 it does you no good when you want to know what 5+5 is. If you learn addition then you can answer yourself in all scenarios

First advice is to read your plants and learn the symptoms of too much light. This will change in every single grow room, each strain and has many contributing factors. So IMO you cannot just go with arbitrary 50% 75% 100% numbers.

DLI (daily light integral) is where you want to start and things will start making more sense. DLI is simply the amount of photons (light energy) a plant receives over a period of..... a day. It clear when you have a longer light period you need less light to achieve the same value than with a shorter light period like photos in flower.

Going against my own advice and giving a simple answer is if you are running 18/6 and change to 12/12 you will need to increase the intensity by 1/3 in order to get the plant the same amount of light per day. This is why in flower we need more light.

Another eg. Is 24/0 light to 12/12 you need to double the amount of light. But 24/0 would require less light than 18/6.

You also need to take into account the photosynthetic rates because plants can only use so much light at a time. This is where you need to learn the symptoms of too much light.

If you want I can dig up some articles but you can simply google DLI cannabis and light stress symptoms cannabis and ask questions that arise from your reading.

The hardest part of learning is not knowing what you dont know. So there are 2 things you can take time to learn about to help answer your own question and understand in the future how you may want to adjust your intensity and photoperiod.

If you have questions on it just post back but nobody can learn it for you and it's no good having an answer if you don't understand it.

Wow, glad I found this thread! Great post!

LED dimmable lighting and watts

LED dimmable lighting and watts

Palgravefarmer

coherent

gorillaglueaaron

🦍

gorillaglueaaron

🦍

Dub_City405

growsince79

gorillaglueaaron

🦍

growsince79

Dub_City405

gorillaglueaaron

🦍

growsince79

PK1

Dub_City405

Attachments

growsince79

Dub_City405

growsince79

Aqua Man

Dothraki

LED dimmable lighting and watts

LED dimmable lighting and watts

Palgravefarmer

coherent

gorillaglueaaron

🦍

gorillaglueaaron

🦍

Dub_City405

growsince79

gorillaglueaaron

🦍

growsince79

Dub_City405

gorillaglueaaron

🦍

growsince79

PK1

Dub_City405

Attachments

growsince79

Dub_City405

growsince79

Aqua Man

Dothraki

Privacy & Transparency

Privacy & Transparency