LED vs HPS

[rootforme]

Just don't be bitter that you were all wrong about the light

 

[Billy the Mountain]

They look good to me. When the light was 8" away they were lightening from the light but since I moved it up they look healthy and are producing fast. The plant is definitely utilizing the additional light.

"While many indoor growers give their plants around 300 to 750 micromoles of light per square meter per second (µmol/m²s) using either double-ended, high-pressure sodium (HPS) or specialized horticulture LED lights, the researchers found that a simpler and more cost effective lighting setup can result in even greater harvests.
Cannabis crops continue to grow in a linear fashion as lighting is intensified at least up to 1,500 µmol/m²s. And that’s achievable by using high intensity, broad-spectrum (white) lights that cost a fraction of what growers spend on those designed specifically for horticulture.
It’s also more than twice the intensity of a 1,060 watt HPS light, which is “almost universally considered the optimal lighting for growing cannabis.”
For their experiment, the team, which involved personnel from the Greenseal Cannabis Company, grew hundreds of plants and kept all other conditions like temperature and soil composition constant. But the crops were exposed to different types of light and light intensity. They discovered that for every additional µmol/m²s that reached the plant, the yield increased by .41 grams.
So when a plant was exposed to an HPS light that delivered an intensity of about 500 µmol/m²s, the total harvest was just under 300 grams. But plants that got 1,500 µmol/m²s from a general purpose LED light produced up to nearly 800 grams."

I'd rather push them to 1500µmol then stay at 500..

There's no sense exceeding 1000 umols without supplemental CO2

 

[rootforme]

There's no sense exceeding 1000 umols without supplemental CO2

And what about when there is supplemental CO2?

 

[Billy the Mountain]

And what about when there is supplemental CO2?

Then the plants can utilize the additional light

 

[bk78]

And what about when there is supplemental CO2?

Can you show us your co2 set up please?

 

[1212ham]

Can you show us your co2 set up please?

And the PAR meter.

 

[rootforme]

And the PAR meter.

I'm not home but it's an active air CO2 kit and an apogee epar which is probably the best par meter on the market.

 

[bk78]

I'm not home but it's an active air CO2 kit and an apogee epar which is probably the best par meter on the market.

So you bought the cheapest Amazon lights and the most expensive par meter? Looking forward to seeing the pics, maybe start a journal so we can follow that as well

 

[rootforme]

So you bought the cheapest Amazon lights and the most expensive par meter? Looking forward to seeing the pics, maybe start a journal so we can follow that as well

Pretty much.. Watch me get just as much yield or more than morons who are spending all that money on a gavita pro.

 

[bk78]

Pretty much.. Watch me get just as much yield or more than morons who are spending all that money on a gavita pro.

You going to start a journal? Or we just have to trust your word?

 

[PJ Diaz]

Have you completed a grow with this setup yet? Having CO2 definitely makes a difference, but it's still too much light, unless the fixtures are inefficient (I'm not familiar with them).

 

[rootforme]

Have you completed a grow with this setup yet? Having CO2 definitely makes a difference, but it's still too much light, unless the fixtures are inefficient (I'm not familiar with them).

No this is my 1st run with this light and my 1st run doing DWC. I admit the plants show some signs of heat stress but it's not light stress. It just may not like 80ﾟ and no AC. Temps have gotten as high as 83. Normally with the lights on it sits at about 79 to 80ﾟ.

 

[bk78]

. I admit the plants show some signs of heat stress

At least we are getting somewhere now

LED vs HPS

Definitely not the camera. Good luck.

www.rollitup.org

 

[Billy the Mountain]

No this is my 1st run with this light and my 1st run doing DWC. I admit the plants show some signs of heat stress but it's not light stress. It just may not like 80ﾟ and no AC. Temps have gotten as high as 83. Normally with the lights on it sits at about 79 to 80ﾟ.

You don't have a heat issue.

Low-mid 80s air temp is ideal for LED lighting

Too much light perhaps?

 

[rootforme]

You don't have a heat issue.

Low-mid 80s air temp is ideal for LED lighting

Too much light perhaps?

Nope

 

[Shaded420]

You don't have a heat issue.

Low-mid 80s air temp is ideal for LED lighting

Too much light perhaps?

No no, def a heat issue. These are not the signs of light stress you are looking for. 1500-2000umol/s is fine.

For a guy who concerns himself with optimal umol etc he sure is clueless about DLI.

Nope

see

 

[PJ Diaz]

No this is my 1st run with this light and my 1st run doing DWC. I admit the plants show some signs of heat stress but it's not light stress. It just may not like 80ﾟ and no AC. Temps have gotten as high as 83. Normally with the lights on it sits at about 79 to 80ﾟ.

Mid 80's is perfect for LED grows. What has you so convinced that it's not light stress?

I don't know your specific strain, but I have one cultivar which will produce much better under lower light conditions. It will begin to shut down with too much photons hitting it.

 

[rootforme]

Mid 80's is perfect for LED grows. What has you so convinced that it's not light stress?

I don't know your specific strain, but I have one cultivar which will produce much better under lower light conditions. It will begin to shut down with too much photons hitting it.

That's strawberry cough

 

[rootforme]

No no, def a heat issue. These are not the signs of light stress you are looking for. 1500-2000umol/s is fine.

For a guy who concerns himself with optimal umol etc he sure is clueless about DLI.

View attachment 5092799



see

I think it's you who are clueless to DLI. Do you think it's capped or something? Maybe educate yourself. Higher DLI equates to higher yield. Although not quite that simple.

 

[Samwell Seed Well]

I think it's you who are clueless to DLI. Do you think it's capped or something? Maybe educate yourself. Higher DLI equates to higher yield. Although not quite that simple.

Indeed, not so simple... just objectivly accurate.