Distance from canopy with 600w open reflectors where’s your sweet spot?

J

Jimmy the vest uk

Well-Known Member
So how far away should we be having our lights? I have had bad results by following a chart I viewed on google saying 30 cm is optimum 42 cm is like the sun and 60cm is the furthest you should go, I have had better buds on some of my shorter plants at times so I’m now experimenting keeping the lights further away, any opinions from own experiences please.
 
sworth

sworth

Well-Known Member
I run two 600w in cool tubes...still my lights are at the very top of my tent, and I still get the odd patch of light burn.
Start with them high , and work your way down, if needs be....
 
J

Jimmy the vest uk

Well-Known Member
so How far away in cm or inches do you have your lights from your canopy with the cool tubes sorry to be specific? Where I’m at is the distance where the main buds become dense really dense no discolouration or extra white hairs being produced, but still after drying and curing are not as tasty as the buds slightly lower. I’m going evan further away this run trying to get them top colas of my canopy dense but still tasting great after dry and cure. I’m hopefull I have it right this time but was just trying to get some distances from other growers, thanks again
 
J

Jimmy the vest uk

Well-Known Member
Wow you can get close with them cool tubes can’t you. Definitely beneficial as your in a tent I have some 6 foot plants right now I’d be screwed if I was in a tent. Thanks for reply
 
J

Jimmy the vest uk

Well-Known Member
Lucky Luke said:
HPS distance chart
https://www.bing.com/images/search?view=detailV2&ccid=29bW5dA0&id=5C9A6759F7209E17AA550DCCF3BAAC6E0C9675C7&thid=OIP.29bW5dA0ZImJDFfdbi6rwwHaJi&q=hps+distance+chart&simid=608007911892779573&selectedIndex=1&ajaxhist=0
Click to expand...
notice on the chart it’s says optimal light distances not heat. So maybe optimal light distance might be that far away but 600w is putting out a lot of heat without a cool tube my plants might be too close in regards to heat from the light but optimal distance is optimal distance
 
Lucky Luke

Lucky Luke

Well-Known Member
Jimmy the vest uk said:
notice on the chart it’s says optimal light distances not heat. So maybe optimal light distance might be that far away but 600w is putting out a lot of heat without a cool tube my plants might be too close in regards to heat from the light but optimal distance is optimal distance
Click to expand...
exactly.

I have a couple of 40c plus days coming up so ill be adjusting the lights higher tonight to account for it.
 
Kingrow1

Kingrow1

Well-Known Member
Those charts assume you had a long veg and well developed plant and root system. Move it futher away for smaller less developed shorter vegged plants.

Too close and leaves over heat, move it till they feel cool to the touch. It is misleading but read your plant, leaves like to be at 21°c, if they feel warm they are getting too much light.

This can be seen with seedlings, at the chart reccomendations they will burn to a crisp as not enough water can be supplied to bring the leaf to optimun temperature.

Ive found this many times, increase light slowly as plants grow, find the distance at which they grow best.

I cannot use those charts with my short veg time, at this plint i find the distance at which the lumens suit the age and let the plant groemw upwatds as it ages and requires more light.

Light meters can help somewhat but you can tell when leaves are getting too much light as they wilt in the dark cycle and before lights out, tips curl and leaves gain a shiny coating of wax.

Play about, youll find your distance, ignore the charts i grow better for not exceeding the leafs light satuation point.

The seasons work like this too, from winter to spring and finally summer you have a steady increase of light. If your veg plants hate the hps work out roughly the lumens at the top of the plant and place them at that required distance so the hps gives the same.

Shit charts really... :-)
 
J

Jimmy the vest uk

Well-Known Member
Kingrow1 said:
Those charts assume you had a long veg and well developed plant and root system. Move it futher away for smaller less developed shorter vegged plants.

Too close and leaves over heat, move it till they feel cool to the touch. It is misleading but read your plant, leaves like to be at 21°c, if they feel warm they are getting too much light.

This can be seen with seedlings, at the chart reccomendations they will burn to a crisp as not enough water can be supplied to bring the leaf to optimun temperature.

Ive found this many times, increase light slowly as plants grow, find the distance at which they grow best.

I cannot use those charts with my short veg time, at this plint i find the distance at which the lumens suit the age and let the plant groemw upwatds as it ages and requires more light.

Light meters can help somewhat but you can tell when leaves are getting too much light as they wilt in the dark cycle and before lights out, tips curl and leaves gain a shiny coating of wax.

Play about, youll find your distance, ignore the charts i grow better for not exceeding the leafs light satuation point.

The seasons work like this too, from winter to spring and finally summer you have a steady increase of light. If your veg plants hate the hps work out roughly the lumens at the top of the plant and place them at that required distance so the hps gives the same.

Shit charts really... :-)
Click to expand...
Thanks for reply
 
thumper60

thumper60

Well-Known Member
Jimmy the vest uk said:
so How far away in cm or inches do you have your lights from your canopy with the cool tubes sorry to be specific? Where I’m at is the distance where the main buds become dense really dense no discolouration or extra white hairs being produced, but still after drying and curing are not as tasty as the buds slightly lower. I’m going evan further away this run trying to get them top colas of my canopy dense but still tasting great after dry and cure. I’m hopefull I have it right this time but was just trying to get some distances from other growers, thanks again
Click to expand...
I run 12in with open hoods,if u start seedling under hids u be surprised how close u can get without bleaching I run my 1k at 16 in open hood
 
Kingrow1

Kingrow1

Well-Known Member
thumper60 said:
well no just saying what I do with no problem
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oh because it sounded like i could veg uder t5's never exceeding 30000 lumens (recomended amount) and then jam it right up into 120000 lumens and the plants wilk love it.

Those charts are shit cause they dont account for variabkes like i just pointed out. Help a grower out dont kill his plants....
 
thumper60

thumper60

Well-Known Member
Kingrow1 said:
oh because it sounded like i could veg uder t5's never exceeding 30000 lumens (recomended amount) and then jam it right up into 120000 lumens and the plants wilk love it.

Those charts are shit cause they dont account for variabkes like i just pointed out. Help a grower out dont kill his plants....
Click to expand...
I agree but over the yrs I have learned that plants started under hids can grow lot closer to light without bleaching ,than any chart I have ever seen,
 
Lucky Luke

Lucky Luke

Well-Known Member
Leaf temps grow best at 21c? I'm surprised that's the case, not saying your wrong as I wouldn't have a clue on that. I'm guessing the transpiration chart would come into play though. Ive found that winter temps like that they grow slower than the high 20's low 30s in spring and Autumn. Summer of cause with the 40c plus is more of a juggle. Ive got a few warm days of 40s today and the next 2 or 3, so raised my light to about 10-12 inches and placed frozen water bottles at the passive air intakes of the tents last night. Its 9:30 AM and its already 30c outside.

But yes, I always use the hand test and depending on the ambient heat and the grow tent heat I can be pretty spot on to this chart. I always look for the first signs of heat stress on the leaves (blistering) at every plant check.

I am using a cooled hood.
Gets to hot here in summer to try to get away with not using one in a tent in my space (no air con and poorly insulated)
 
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Lucky Luke

Lucky Luke

Well-Known Member
This is my tallest plant atm and is closet to the light. If you zoom in you can see some minor blistering of the top leaves. But remember I'm in Summer and its normal for me to see low 30s C in the tent.
DSC00921.JPG
 
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Kingrow1

Kingrow1

Well-Known Member
Lucky Luke said:
Leaf temps grow best at 21c? I'm surprised that's the case, not saying your wrong as I wouldn't have a clue on that. I'm guessing the transpiration chart would come into play though. Ive found that winter temps like that they grow slower than the high 20's low 30s in spring and Autumn. Summer of cause with the 40c plus is more of a juggle. Ive got a few warm days of 40s today and the next 2 or 3, so raised my light to about 10-12 inches and placed frozen water bottles at the passive air intakes of the tents last night. Its 9:30 AM and its already 30c outside.

But yes, I always use the hand test and depending on the ambient heat and the grow tent heat I can be pretty spot on to this chart. I always look for the first signs of heat stress on the leaves (blistering) at every plant check.

I am using a cooled hood.
Gets to hot here in summer to try to get away with not using one in a tent in my space (no air con and poorly insulated)
Click to expand...
Re-read leaves like to be at 21`c the world over, they use transpiration to get to this temp, where was i saying the air needs to be that temp, its about their internal cooling and thats why if they dont feel cool to the touch they are struggling.

Fyi your leaves look thin and droopy, called heat stress.

I also present the acclimitization problem that is well known when transfering from lower lumens to higher lumens, you make it midday equator sun level for 12 hours a day, nature and dli intergral says your wrong to do this, calculate your umols and youll grow better...
 
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