Need some help with tent size for HLG 650r

[nac]

Hi guys

I'm gonna get a HLG 650r and i could use some help on tent size. Their site says it covers 5x5 flowering but I'm getting the impression that it won't be super efficient in the outer part of such a size. I also read some guy say that 4x4 is too small for a 650r. Thoughts?

 

[dbz]

Hi guys

I'm gonna get a HLG 650r and i could use some help on tent size. Their site says it covers 5x5 flowering but I'm getting the impression that it won't be super efficient in the outer part of such a size. I also read some guy say that 4x4 is too small for a 650r. Thoughts?

a 4x4 is just about 40 watts per sq ft. That may be towards the top of what you want without LEDs. Fortunately I believe they come with a dimmer and you could dim 10 percent if the plants don't seem to like it.
I think it would flower a 5x5 fine, but you may could utilize a bit more light at that point. Personally I'd stick it in a 4x4.
My small 3x3 is using near 45 watts per sq ft and the plants have handled it just fine the whole time.

 

[nac]

a 4x4 is just about 40 watts per sq ft. That may be towards the top of what you want without LEDs. Fortunately I believe they come with a dimmer and you could dim 10 percent if the plants don't seem to like it.
I think it would flower a 5x5 fine, but you may could utilize a bit more light at that point. Personally I'd stick it in a 4x4.
My small 3x3 is using near 45 watts per sq ft and the plants have handled it just fine the whole time.

Forgive me for being uninformed but in what way is the watts per sq ft relevant? Could you maybe elaborate on that. Also you don't think it would have a heat problem in a 4x4 with this LED? Or would you combine it with some sort of air condition? The previous LED i had was very bad so i didn't need air condition.

 

[dbz]

Forgive me for being uninformed but in what way is the watts per sq ft relevant? Could you maybe elaborate on that. Also you don't think it would have a heat problem in a 4x4 with this LED? Or would you combine it with some sort of air condition? The previous LED i had was very bad so i didn't need air condition.

Watts per square foot isn't the most reliable metric. In truth none are, especially what manufacturer's say about their lights. However when dealing with quality lights usually you want to shoot for at least 30 watts per square foot..if you start going much above 45 your plants will have a hard time without CO2. With lower quality lights, like cheap blurples or something you probably want a minimum of closer to 40 watts per sq ft.

HLG is a good company, and their recommendations I would say are probably their max flower recommended size.

Well as far as the heat goes, it all has to do with your extraction capacity and ambient room temperature more than anything. When I was running 420 watts in a 3x3 which is pretty damn intense, the plants liked it fine, but my 4 inch extraction fan wasn't enough. A 6 inch was though.

Another thing that a lot of people overlook is the lack of IR in most LED spectrums and if it is present to a much lesser degree than an HPS. So IR (infrared) light heats up the surface of leaves. Which is why when growing with HPS 74-77f may do you well in temp. With LED though, with the lack of IR the canopy or leaf temp is much closer to the ambient temp. So while under an HPS you may want 77 ambient to get an 84 degree leaf temperature, with LED your ambient temperature will be almost the same as your leaf temp. So you want to be running closer to 82-86f degrees.

 

[nac]

Watts per square foot isn't the most reliable metric. In truth none are, especially what manufacturer's say about their lights. However when dealing with quality lights usually you want to shoot for at least 30 watts per square foot..if you start going much above 45 your plants will have a hard time without CO2. With lower quality lights, like cheap blurples or something you probably want a minimum of closer to 40 watts per sq ft.

HLG is a good company, and their recommendations I would say are probably their max flower recommended size.

Well as far as the heat goes, it all has to do with your extraction capacity and ambient room temperature more than anything. When I was running 420 watts in a 3x3 which is pretty damn intense, the plants liked it fine, but my 4 inch extraction fan wasn't enough. A 6 inch was though.

Another thing that a lot of people overlook is the lack of IR in most LED spectrums and if it is present to a much lesser degree than an HPS. So IR (infrared) light heats up the surface of leaves. Which is why when growing with HPS 74-77f may do you well in temp. With LED though, with the lack of IR the canopy or leaf temp is much closer to the ambient temp. So while under an HPS you may want 77 ambient to get an 84 degree leaf temperature, with LED your ambient temperature will be almost the same as your leaf temp. So you want to be running closer to 82-86f degrees.

Are you saying i should aim for a temperatures of 82 - 86 fahrenheit (my 27 - 30 celsius) even during flowering with an LED? I was not aware of that. Is there anything else i should know when using LED compared to HPS?

 

[Dopesmoka]

Are you saying i should aim for a temperatures of 82 - 86 fahrenheit (my 27 - 30 celsius) even during flowering with an LED? I was not aware of that. Is there anything else i should know when using LED compared to HPS?

Nope just for veg you don’t want to bake your terpenes away
I would get the 5x5 the light can veg a 7x7 if I’m not mistaken

 

[dbz]

Are you saying i should aim for a temperatures of 82 - 86 fahrenheit (my 27 - 30 celsius) even during flowering with an LED? I was not aware of that. Is there anything else i should know when using LED compared to HPS?

Yeah in flower with led you want low to mid 80s. Once again this is essentially the same temp to plant's leaves as an HPS at 75-78. It is some of the most criminally underspread info on growing. Without the high levels of IR spectrum an HPS gives off the leaf temps are drastically different between the two.
Obv if it were for veg you could easily accommodate a much larger area.

 

[Rocket Soul]

Yeah in flower with led you want low to mid 80s. Once again this is essentially the same temp to plant's leaves as an HPS at 75-78. It is some of the most criminally underspread info on growing. Without the high levels of IR spectrum an HPS gives off the leaf temps are drastically different between the two.
Obv if it were for veg you could easily accommodate a much larger area.

I agree but like to bring a bit of nuance: with leds you generally need to raise temps as you up intensity if you wanna make sure you have a happy plant. Low temps generally leads to High Irradiance Response; HIR; which means purpling stems and all the usual overcooked plant signs.
On low intensity low temps the plants metabolism dont have a problem keeping up but at highet intensity you really need to keep the temps up. This is a thing sorta like growing with extra CO2 you need a higher metabolism.

 

[nac]

Yeah in flower with led you want low to mid 80s. Once again this is essentially the same temp to plant's leaves as an HPS at 75-78. It is some of the most criminally underspread info on growing. Without the high levels of IR spectrum an HPS gives off the leaf temps are drastically different between the two.
Obv if it were for veg you could easily accommodate a much larger area.

Okay i will run higher temps then! I'm trying to find a tent that is 5x5 and more than 8x height because i'm worried the distance plants needs to be from the LED is too much. I'm only gonna have around 25 inches of plant height to work with. What do you think?