Just pulled the trigger....

KonopCh

Well-Known Member
How far can be center from one strip to center of another strip? Optimal and maximal distance. Asking for both, single row and double row strips.
 

nfhiggs

Well-Known Member
How far can be center from one strip to center of another strip? Optimal and maximal distance. Asking for both, single row and double row strips.
There is no "optimal", just what distance you choose to space them will determine the distance from the lights that you get good uniformity. Buy however many you want, space them equally across the top of your space and run them at about 20-25W per square foot in veg, and 30-35W per square foot in flower.
 

skoomd

Well-Known Member
There is no "optimal", just what distance you choose to space them will determine the distance from the lights that you get good uniformity. Buy however many you want, space them equally across the top of your space and run them at about 20-25W per square foot in veg, and 30-35W per square foot in flower.
Yeah, this is solid info. Optimal is simply evenly spacing them and making them cover as much of the tent/grow area as possible for max uniformity. If you want to figure out the intensity, which can be tricky with DIY LED because of all the variables, get a lux meter and convert lux to PPFD. You'd be surprised what results you get.

But as a general rule of thumb, if you're at 30-40w per square foot, 12-24" is where you'll want to be at in flowering. Further if you are using fewer LEDs driven harder, closer if you use a lot of LEDs and drive them soft.

I get 700-730PPFD at 12-18" with 35 watt per square foot. 500PPFD at 36".
 

KonopCh

Well-Known Member
@jarvild that's nice, where did you get those heatsinks?

@nfhiggs @skoomd I have 120x120cm tent, and at the one end I will use 150W of 6x Citizen 1212 (should cover 30cm wide, so I left with 90cm for strips), and at the other end I want 250W of single row strips - 5 rows of 1120mm strips on HLG-240H-C1050A. So this should be covered with strips 15cm apart from center to center. I SCROG plants, but I need 20-25cm hard colas, it this achivable with that setup I described?
 

Randomblame

Well-Known Member
Yepp, easily!

@jarvild that's nice, where did you get those heatsinks?

@nfhiggs @skoomd I have 120x120cm tent, and at the one end I will use 150W of 6x Citizen 1212 (should cover 30cm wide, so I left with 90cm for strips), and at the other end I want 250W of single row strips - 5 rows of 1120mm strips on HLG-240H-C1050A. So this should be covered with strips 15cm apart from center to center. I SCROG plants, but I need 20-25cm hard colas, it this achivable with that setup I described?
 

skoomd

Well-Known Member
@jarvild that's nice, where did you get those heatsinks?

@nfhiggs @skoomd I have 120x120cm tent, and at the one end I will use 150W of 6x Citizen 1212 (should cover 30cm wide, so I left with 90cm for strips), and at the other end I want 250W of single row strips - 5 rows of 1120mm strips on HLG-240H-C1050A. So this should be covered with strips 15cm apart from center to center. I SCROG plants, but I need 20-25cm hard colas, it this achivable with that setup I described?
400w of cobs/strips is pretty light for that size space. You'd want closer to 500w or even 600w for flower.
 

KonopCh

Well-Known Member
400w of cobs/strips is pretty light for that size space. You'd want closer to 500w or even 600w for flower.
I only need maximum 35000 LUX or around 500 PPFD. As I grow autos, in the end of flowering 35000 LUX is great! And I want to recycle my old 1212 light.
 

jarvild

Well-Known Member
@jarvild that's nice, where did you get those heatsinks?

@nfhiggs @skoomd I have 120x120cm tent, and at the one end I will use 150W of 6x Citizen 1212 (should cover 30cm wide, so I left with 90cm for strips), and at the other end I want 250W of single row strips - 5 rows of 1120mm strips on HLG-240H-C1050A. So this should be covered with strips 15cm apart from center to center. I SCROG plants, but I need 20-25cm hard colas, it this achivable with that setup I described?
Heatsink USA. Each sink cost me around $5.10 delivered. They may be overkill for cooling strips but from my experience heat is the number one destroyer of electronics so I tend to overcool everything.
 

skoomd

Well-Known Member
Heatsink USA. Each sink cost me around $5.10 delivered. They may be overkill for cooling strips but from my experience heat is the number one destroyer of electronics so I tend to overcool everything.
Yeah I paid $5-6 per heatsink to cool my strips. 24" long 1" wide.



Works a good bit better than U frame for not much extra cost. Lower profile too for thinner/sleeker look.

My strips @ 75% max current (2 foot single rows) get to 50c after a day. My friends strips using U frame (4 foot dbl row strips) at 50% max current get to 65c after a day.
 

KonopCh

Well-Known Member
Aaaaah, too bad, I am from EU. I want "overcool" things too.
I plan to use 2x560mm strips on 1120mm ALU U channel. 45 x 25 x 2,5 mm or 70 x 25 x 3 mm I can get for nice price... But 50°C is little too hot I think... At 1.05A.
 

skoomd

Well-Known Member
Aaaaah, too bad, I am from EU. I want "overcool" things too.
I plan to use 2x560mm strips on 1120mm ALU U channel. 45 x 25 x 2,5 mm or 70 x 25 x 3 mm I can get for nice price... But 50°C is little too hot I think... At 1.05A.
Im at 50c at 1.34A. At 1.05A it's probably 40-43c or so.
 

jarvild

Well-Known Member
Aaaaah, too bad, I am from EU. I want "overcool" things too.
I plan to use 2x560mm strips on 1120mm ALU U channel. 45 x 25 x 2,5 mm or 70 x 25 x 3 mm I can get for nice price... But 50°C is little too hot I think... At 1.05A.
My U-channel build run around 42 C @ 1.25 amps with 8 strips.
DSCN0843.JPG
 

skoomd

Well-Known Member
My U-channel build run around 42 C @ 1.25 amps with 8 strips.
View attachment 4134218
Hmm interesting. i am using an Ir gun to take temps though, not an actual probe or anything. But i wonder if my friends are so hot because they're double row? But i feel like with 2" U frame like he is using would be the same as single row strips with 1"?

Do you have a fan blowing on them? I dont at the moment, but when I do the temps drop to around 40c.
 

Aolelon

Well-Known Member
Hmm interesting. i am using an Ir gun to take temps though, not an actual probe or anything. But i wonder if my friends are so hot because they're double row? But i feel like with 2" U frame like he is using would be the same as single row strips with 1"?

Do you have a fan blowing on them? I dont at the moment, but when I do the temps drop to around 40c.
IR isn't the best to take temps on with a reflective surface.
 

skoomd

Well-Known Member
IR isn't the best to take temps on with a reflective surface.
Yeah i think that's the issue. I think nfhiggs said you can just use a sharpie and make a black spot on the aluminum and it should work with the Ir gun though. Ill do that and report back. It's weird that the Ir gun seems to measure the driver perfectly (which is alum) but the heatsinks are probably off.
 

Aolelon

Well-Known Member
Yeah i think that's the issue. I think nfhiggs said you can just use a sharpie and make a black spot on the aluminum and it should work with the Ir gun though. Ill do that and report back. It's weird that the Ir gun seems to measure the driver perfectly (which is alum) but the heatsinks are probably off.
Yep or some kind of black paint. anything to stop it from reflecting away. Yea it is kind of weird, I was going to say I wonder if its cause the matte finish on the driver, but the heatsinks have that same finish it looks like. Either way I would try it and see if it differs at all.
 
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