LEDs vs HPS - quality of extracts

[MikeGanja]

I use HPS for bloom. Problem is that my grow room gets too hot during the summer months. I have considered an AC unit but unfortunately it would add too many amps. So far, I have closed down the grow during the summer.


My interest is focused on extracts. I make extracts of the entire harvest and I only care about the quality of the terps. The density of buds is not important since everything is extracted as soon as soon it has dried enough.


I have calculated that if I switch to LEDs, the grow room would be cool enough even during the summer. I guess that being able to grow during 12 months instead of 8 months would compensate for any lower efficiency of the LEDs.


Can I expect the same quality of the extracted terps with HPS instead of LEDs?

 

[canadian1969]

I have calculated that if I switch to LEDs, the grow room would be cool enough even during the summer

How have you calculated this?

 

[MikeGanja]

I used the British Terminal Unit formula to convert watts to BTU.

I have 2 x 600 watt HPS with cooltubes in my grow room. The LED is marketed as a replacement for 1000w HPS with the power consumption of 630 w.

1200 w x 3.41214 = 4095 BTU/h
compared to
630 w x 3.41214 = 2150 BTU/h
Then I used an online calculator for further calculations with size of room and temperatures and estimated how many BTUs it takes to heat the grow room a certain amount of degrees.

I have tried LEDs in the past and it produced quite some heat and crappy yield. But to be honest, that was cheap china stuff several years ago. I don’t expect 630 watt LED to replace 100 watt HPS in yield but I am still curious of the quality of extract from LED grow.

 

[Ryante55]

I used the British Terminal Unit formula to convert watts to BTU.

I have 2 x 600 watt HPS with cooltubes in my grow room. The LED is marketed as a replacement for 1000w HPS with the power consumption of 630 w.

1200 w x 3.41214 = 4095 BTU/h
compared to
630 w x 3.41214 = 2150 BTU/h
Then I used an online calculator for further calculations with size of room and temperatures and estimated how many BTUs it takes to heat the grow room a certain amount of degrees.

I have tried LEDs in the past and it produced quite some heat and crappy yield. But to be honest, that was cheap china stuff several years ago. I don’t expect 630 watt LED to replace 100 watt HPS in yield but I am still curious of the quality of extract from LED grow.

If your running 1200w of hps you should replace that with 1000w of dimmable LED if heat is an issue you can always dim it down expect to spend at least $1500 maybe $2000 on led if your not ready to invest that much stick with your hps. I don't want to advertise for anyone but I recommend any light that uses the Samsung lm561c diodes

 

[canadian1969]

I agree with Ryante55
also putting the drivers outside the grow will help thermally
Have you seen the new Quantum Boards? (they use the lm561c)
https://horticulturelightinggroup.com/products/hlg-550

 

[MikeGanja]

Thank you for your advice, Ryantee55 and Canadian1969!

It is a lot of money but I am willing to invest if it means that I can grow during the summer. I keep telling myself that it’s a good investment because I can grow year-round.

I found some info on Heliospectras LEDs that looks very promising. Heliospectras business concept, the option to experiment with different wavelengths for optimal quality is interesting, but I can’t tell if it’s snake oil or not.

Reading your answers, I understand that the industry of LED lights for cannabis has developed a lot since my last try. The Quantum board is new to me. Great with the possibility to unscrew the drivers and have them outside. Also, I appreciate that the Quantum boards have a huge heat sink instead of internal fans

 

[The Hippy]

Thank you for your advice, Ryantee55 and Canadian1969!

It is a lot of money but I am willing to invest if it means that I can grow during the summer. I keep telling myself that it’s a good investment because I can grow year-round.

I found some info on Heliospectras LEDs that looks very promising. Heliospectras business concept, the option to experiment with different wavelengths for optimal quality is interesting, but I can’t tell if it’s snake oil or not.

Reading your answers, I understand that the industry of LED lights for cannabis has developed a lot since my last try. The Quantum board is new to me. Great with the possibility to unscrew the drivers and have them outside. Also, I appreciate that the Quantum boards have a huge heat sink instead of internal fans

I agree ......Fans in grow room lighting is just a stupid concept from the git go. "sink"....or swim.....lol

 

[bez420]

Stupid ?, but have you tried only running the lights at night? Or a split unit Ac?

But no, you'll never get the same intensity from LED's. There for less crystals, or whatever the scientific term is. But, if your getting 3 or 4 more months, then more than compensates!

 

[bez420]

I agree ......Fans in grow room lighting is just a stupid concept from the git go. "sink"....or swim.....lol

Fans are more important for strengthening your stalks than cooling.

 

[ttystikk]

Stupid ?, but have you tried only running the lights at night? Or a split unit Ac?

But no, you'll never get the same intensity from LED's. There for less crystals, or whatever the scientific term is. But, if your getting 3 or 4 more months, then more than compensates!

Have you gotten with LED? I'm betting not or you wouldn't be caught dead saying this.

 

[ttystikk]

Fans are more important for strengthening your stalks than cooling.

The fans in question are those for cooling the light fixtures.

Not the same as circulation fans in the room.

 

[ttystikk]

Thank you for your advice, Ryantee55 and Canadian1969!

It is a lot of money but I am willing to invest if it means that I can grow during the summer. I keep telling myself that it’s a good investment because I can grow year-round.

I found some info on Heliospectras LEDs that looks very promising. Heliospectras business concept, the option to experiment with different wavelengths for optimal quality is interesting, but I can’t tell if it’s snake oil or not.

Reading your answers, I understand that the industry of LED lights for cannabis has developed a lot since my last try. The Quantum board is new to me. Great with the possibility to unscrew the drivers and have them outside. Also, I appreciate that the Quantum boards have a huge heat sink instead of internal fans

Don't get those.

Look into lighting from HLG, Johnson Grow Lights, Northern Grow Lights. They sell the Quantum Boards that you've heard of.

I've grown under HPS, MH, CMH/CDM, CFL and T5.

When I started using LED lights, in my case COB LED, I wasn't the only one who noticed increased terpenes and more resin production. Everyone else did, too.

Better spectrum, less watts, more resin when grown with modern full spectrum LED such as quantum boards or COB LED.

That's personal, hands on experience from multiple runs.

 

[BobCajun]

You need about 2/3 the wattage with LED as with HPS, due to greater micromoles of light per watt with LED. And yeah you usually get more terps with LED. Blue light produces more resin and terps than red, so I would go with a high color temperature type LED, something like 5000k, if that's your goal. The high color temp ones are also more efficient than lower ones. You really only need a small amount of red, enough to activate the flowering response.

A lot of grow lights emphasize the red part of the spectrum but in fact red just doesn't produce as much growth as blue. You need some, to flower, but not much really, just some. In fact I've read that it's possible to use pure blue for the entire photoperiod as long as you turn some red lights on for like 5 minutes at the end right before the dark period, plants will flower normally. Not a very practical way to do things but in theory possible.

 

[ttystikk]

I did very well with 3500K 80 CRI chips. Consider supplementing with UV T5 lighting to maximize resin production.

 

[MikeGanja]

Stupid ?, but have you tried only running the lights at night? Or a split unit Ac?

But no, you'll never get the same intensity from LED's. There for less crystals, or whatever the scientific term is. But, if your getting 3 or 4 more months, then more than compensates!

Yes, I do run the lights on nights. It helps, but not enough. A split AC unit would be my first choice but problem is that the electricity system can’t take the extra load from the AC. Also, I rent the place so I must avoid making any holes thru the concrete walls.

After reading the answers to this thread I am convinced that LEDs are the way to go, at least during the summer.

 

[MikeGanja]

Don't get those.

Look into lighting from HLG, Johnson Grow Lights, Northern Grow Lights. They sell the Quantum Boards that you've heard of.

I've grown under HPS, MH, CMH/CDM, CFL and T5.

When I started using LED lights, in my case COB LED, I wasn't the only one who noticed increased terpenes and more resin production. Everyone else did, too.

Better spectrum, less watts, more resin when grown with modern full spectrum LED such as quantum boards or COB LED.

That's personal, hands on experience from multiple runs.

I think I follow your advice and choose the Quantum boards. I have read nothing but positive reviews about them. Heliospectra is less known and more expensive.

Sounds great about the resin production. I needed to hear that information before investing.

 

[MikeGanja]

You need about 2/3 the wattage with LED as with HPS, due to greater micromoles of light per watt with LED. And yeah you usually get more terps with LED. Blue light produces more resin and terps than red, so I would go with a high color temperature type LED, something like 5000k, if that's your goal. The high color temp ones are also more efficient than lower ones. You really only need a small amount of red, enough to activate the flowering response.

A lot of grow lights emphasize the red part of the spectrum but in fact red just doesn't produce as much growth as blue. You need some, to flower, but not much really, just some. In fact I've read that it's possible to use pure blue for the entire photoperiod as long as you turn some red lights on for like 5 minutes at the end right before the dark period, plants will flower normally. Not a very practical way to do things but in theory possible.

Interesting information! The LED light industry has taken a huge step forward since my last try. I really need to read some literature on wavelengths and cannabis.

 

[MikeGanja]

I did very well with 3500K 80 CRI chips. Consider supplementing with UV T5 lighting to maximize resin production.

Should I run the UV T5 supplement lights for only short periods every day in the end of the flowering cycle or the whole 12-12 period?

 

[ttystikk]

Should I run the UV T5 supplement lights for only short periods every day in the end of the flowering cycle or the whole 12-12 period?

The whole period. Be sure to properly harden your plants off to the light.

 

[BobCajun]

Should I run the UV T5 supplement lights for only short periods every day in the end of the flowering cycle or the whole 12-12 period?

Nah don't listen to Stikky. UV is a waste of money and will likely cause you personal harm. Leave the cataracts to Stikky. Never heard anybody complain that LED grown weed, which has no UV at all, is weak. There's UV outdoors, but outdoor weed is usually weaker than indoor with LED, so what does that tell you?