Help please. New to HPS - Light distance/heat concerns

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Dr. Doob

Dr. Doob

Member
I used a 300w led on my last grow, the results were 32g of dry bud, great quality but just tiny buds. Thought I'd give hps a go to see what differences there are aside from the obvious bigger yield. My set up is a 60x60x150 tent, lumii 600w hps dimmable ballast, RAM carbon filter attatched to a 4" RAM extraction fan, 6" rotating fan, soil/perlite mix, 17L pots, biobizz nutrients.
I was planning on only using the hps at 400w due to what I've read about heat problems but if anyone disagrees tell me please.
How far would anyone recommend keeping the hps lights from the canopy top?
 
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Skittles22

Member
Keep the light a meter away, trust me when i say those lights are hot and you need all the fan you can get if your growing in a tent, i have my carbon filter awell as 1 big desk fan hanging upside down oscilating and under foaliage fan to circulate air at the bottom, people will always say led is better but they just arnt, all the best big grow companies use hps, if you dont belive me do some research bro, happy growing
 
.Smoke

.Smoke

Well-Known Member
You're going to need an air cooled hood to run in the tent.
That being said,
Run @ 600w all the time.
Seedlings =12k Lux. Gradually increasing to no more than 60k Lux by week 2-3 depending on growth. Run anywhere from 55-60k Lux the whole grow.

All of this is assuming you got an air cooled hood and can get the light close enough.

I run 3.3kW of HPS/MH/CMH.
My lights vary from 36"-10" above the canopy depending on the situation.

It's about Lux/Par amounts @ the canopy, not light height. Grab a meter off Amazon for $20. You'll be glad you did.

Follow those numbers and you'll get a helluva lot more smoke than last time.

Link to my grow is in my signature if you want to see results from those suggestions.

Best of luck to you and good choice on switching to HPS. :bigjoint:
 
FastFreddi

FastFreddi

Well-Known Member
.Smoke said:
You're going to need an air cooled hood to run in the tent.
That being said,
Run @ 600w all the time.
Seedlings =12k Lux. Gradually increasing to no more than 60k Lux by week 2-3 depending on growth. Run anywhere from 55-60k Lux the whole grow.

All of this is assuming you got an air cooled hood and can get the light close enough.

I run 3.3kW of HPS/MH/CMH.
My lights vary from 36"-10" above the canopy depending on the situation.

Follow those numbers and you'll get a helluva lot more smoke than last time.

It's about Lux/Par amounts @ the canopy, not light height. Grab a meter off Amazon for $20. You'll be glad you did.

Link to my grow is in my signature if you want to see results from those suggestions.

Best of luck to you and good choice on switching to HPS. :bigjoint:
Click to expand...
I just did the opposite...2x600w cool hoods switched out for 2x Timber 3vl's, 2x mars hydro sp150's and an sp250.
My quality of Bud has GONE UP.
BOTH styles of lighting have their place. I changed out due to heat issues.
These are my initial learning curve plants. Day 4 week 4...leds work Bro.
FF20200303_211648.jpg20200303_090049.jpg20200303_070244.jpg
 
.Smoke

.Smoke

Well-Known Member
FastFreddi said:
I just did the opposite...2x600w cool hoods switched out for 2x Timber 3vl's, 2x mars hydro sp150's and an sp250.
My quality of Bud has GONE UP.
BOTH styles of lighting have their place. I changed out due to heat issues.
These are my initial learning curve plants. Day 4 week 4...leds work Bro.
FFView attachment 4495353View attachment 4495354View attachment 4495355
Click to expand...
Agreed.
Both have their places. Just different seeing someone go to hps from led and figured I'd give a few pointers on how he can make that style work...
20200301_031403.jpg 20200301_031459.jpg 20200301_031526.jpg
 
Dr. Doob

Dr. Doob

Member
Skittles22 said:
Keep the light a meter away, trust me when i say those lights are hot and you need all the fan you can get if your growing in a tent, i have my carbon filter awell as 1 big desk fan hanging upside down oscilating and under foaliage fan to circulate air at the bottom, people will always say led is better but they just arnt, all the best big grow companies use hps, if you dont belive me do some research bro, happy growing
Click to expand...
whats typical temperature in your tent with that setup using the 2 fans and extractor too?
 
Rum Nugginz

Rum Nugginz

Active Member
Dr. Doob said:
I used a 300w led on my last grow, the results were 32g of dry bud, great quality but just tiny buds. Thought I'd give hps a go to see what differences there are aside from the obvious bigger yield. My set up is a 60x60x150 tent, lumii 600w hps dimmable ballast, RAM carbon filter attatched to a 4" RAM extraction fan, 6" rotating fan, soil/perlite mix, 17L pots, biobizz nutrients.
I was planning on only using the hps at 400w due to what I've read about heat problems but if anyone disagrees tell me please.
How far would anyone recommend keeping the hps lights from the canopy top?
Click to expand...
you should be ok with that size tent, just keep the light raised up high
 
Rum Nugginz

Rum Nugginz

Active Member
As long as you use at least a 4'x4'x78 tent, your temps should be ok as long as you have a decent exhaust fan. I used a 600 watt HPS in a 3'x3'x7' tent and my temps never got above 79 degrees F but I ended up with light burn, not heat damage, but the light was too strong because of the walls of the grow tent reflecting it back onto the plant (like it should) but in the 3x3 it was just too intense. Some people may have different opinions, but I am just giving you an example of what I have encountered. Good Luck !!!!
 
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spek9

Well-Known Member
Rum Nugginz said:
As long as you use at least a 4'x4'x78 tent, your temps should be ok as long as you have a decent exhaust fan. I used a 600 watt HPS in a 3'x3'x7' tent and my temps never got above 79 degrees F but I ended up with light burn, not heat damage, but the light was too strong because of the walls of the grow tent reflecting it back onto the plant (like it should) but in the 3x3 it was just too intense. Some people may have different opinions, but I am just giving you an example of what I have encountered. Good Luck !!!!
Click to expand...
When running HID lamps, the two most important things to consider regarding temperatures are A) What is the ambient temperature of the room the tent is in, and B) Where will the heated exhaust go.

For example, my basement temperature is a consistent 52-54F on the floor. All of my tents (2x4x5' 400W MH, 4x4x7' 600W HPS and 4x4x7' 1000W HPS) have a 'shelf' on the bottom, holding the plants 8" above the floor, where the lights-off temps are about 58-60F.

At lights on, the 400W and 600W hover at about 72-74F, and the 1000W is around 76-78F. I exhaust everything outside through a chimney, and bring in air passively from the surrounding area of the basement.

If you're burning a 600W in a 3x3' tent, but the ambient air temperature is 72F or above, with the lamp on and exhausting into a small space surrounding the tent, your temps will be close to above the danger level.
 
Rum Nugginz

Rum Nugginz

Active Member
spek9 said:
When running HID lamps, the two most important things to consider regarding temperatures are A) What is the ambient temperature of the room the tent is in, and B) Where will the heated exhaust go.

For example, my basement temperature is a consistent 52-54F on the floor. All of my tents (2x4x5' 400W MH, 4x4x7' 600W HPS and 4x4x7' 1000W HPS) have a 'shelf' on the bottom, holding the plants 8" above the floor, where the lights-off temps are about 58-60F.

At lights on, the 400W and 600W hover at about 72-74F, and the 1000W is around 76-78F. I exhaust everything outside through a chimney, and bring in air passively from the surrounding area of the basement.

If you're burning a 600W in a 3x3' tent, but the ambient air temperature is 72F or above, with the lamp on and exhausting into a small space surrounding the tent, your temps will be close to above the danger level.
Click to expand...
I no longer use the 3x3, I recently upgraded to a 4"x4"x7", but yes ambient room temps do make the difference. the ambient room temp was approx. 60 degrees F with my a/c. If the a/c wasn't running, It did get into the mid-high 80's very quickly. Also true that exhaust should be vented to the outside
 
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spek9

Well-Known Member
Rum Nugginz said:
I no longer use the 3x3, I recently upgraded to a 4"x4"x7", but yes ambient room temps do make the difference. the ambient room temp was approx. 60 degrees F with my a/c. If the a/c wasn't running, It did get into the mid-high 80's very quickly. Also true that exhaust should be vented to the outside
Click to expand...
My basement is so consistently cool, I don't even attach my air cooled hoods to my exhaust filters/fans.
 
Rum Nugginz

Rum Nugginz

Active Member
spek9 said:
My basement is so consistently cool, I don't even attach my air cooled hoods to my exhaust filters/fans.
Click to expand...
I wish I had a basement I could use for growing cannabis, but for now I will stick to wintertime grows, when I can just open the window and have instant temp control. Less humidity when growing indoors in the winter also, just saying
 
Rum Nugginz

Rum Nugginz

Active Member
Wattzzup said:
HPS approx 16-20 inches is where I keep mine. I keep a small fan blowing between light and plant.
Click to expand...
It also depends on which type of reflector you are using, I use an open reflector with no glass and end up having to raise it right up to the ceiling most of the time, strain dependent of course, some strains can handle more light. Anyhow, if you use an air cooled reflector with a glass shield you can get the light much closer than with an open one. The plants do get more get more UV light with an open reflector without the shield, imo
 
Wattzzup

Wattzzup

Well-Known Member
I have a light a fan and a vent. No coolers, no hoods, no shields.

3 feet is too far away IMO for the light. My 600 calls for 14-22 or something like that.
 
.Smoke

.Smoke

Well-Known Member
600W MH (air-cooled/glass covered)
4'x4' veg tent
Light distance = 18in/54k-58k lux @ canopy.
20200307_043507.jpg
After week 2-3, there's no reason to not run your lights @ the optimum/maximum amount you can generate that your plants can handle with no stress.
bongsmilie
 
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