horticultural veg light build, lost...stumped... I need advice, come on in!

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Bourbon 2

Well-Known Member
Guys I really appreciate all of your advice, this is great and vast knowledge :)
Beginning today I will follow your recommendations, 1st by ramping down the exhaust fan and lowering the light fixture a bit to increase the temp. One thing that I do is measure the ph of my feedings and lower as needed before applying.
I'm trying an experiment with this run to see if the yield will increase or equal my earlier run. I'm not lollipopin, topping or major defoliation as before. I was disappointed with one of my plants that I spent much time on to increase the yield, plant looked great but still disappointed..
 

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1212ham

Well-Known Member
Randomblame said:
The most issues with LED's are caused by the missing heat radiation, that's right. But there are other ways to deal with it as to add 100-200w of IR. A 1000w HPS has around 20% heat radiation, its not a good idea to mimic this with LED's.
You need to keep an eye on the humidity in your grow area. That was not so important with HPS because of its radiated heat.
Click to expand...
Would incandescent be any good as a source of IR in a small tent? I'm guessing most of the heat is convection and conduction rather than IR?
Very good thread!
 
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Randomblame

Randomblame

Well-Known Member
1212ham said:
Would incandescent be any good as a source of IR in a small tent? I'm guessing most of the heat is convection and conduction rather than IR?
Very good thread!
Click to expand...
The most efficient way to bring the temps up is probably an efficient ceramic heater. Incandescent bulbs produce a lot of heat but they also produce a lot of far-red which could cause stress. I've not tested it but to increase canopy temps by 5°C you would probably need a 60-100w bulb for a 2x 2' area and you need to bring the bulb close to the plants(stretching effect) or use at least a fan to distribute the heat evenly otherwise the heat gets sucked out by the exhaust fan.
Actually we use LED's to get rid of the heat radiated by HPS/CMH bulbs. They have 20% light in the 800nm range which is almost pure heat but most SPD chart show only the output inside the PAR range.

In the end you can get the heat for free when you reduce your exaust fan and hang the light as close as possible above the canopy. In the worst case you can mount a fan under the ceiling blowing downwards to make better use of the heat. If you add a few sugar/turbo yeast bottles in winter you can also stop the exhaust fan completely to keep the heat inside your tent and profit from CO².
In the end watts are watts and I have only problems with too low ambient temps in veg. With 800-1000μMol/s intensity (35-40w/sft) and 12-16" distance I can get at least 25-26°C leaf temps within a few hours.
 
oldbeancounter

oldbeancounter

Well-Known Member
Cutter for whatever reason never got back to me so this is taking far longer that I hoped.
HLG came through with red LED's(just got a few for now) and UVA so that part is ok it is just 390nm to 450nm I can't seem to find on a strip LED at decent price.
Anyone have any ideas that panned out for them?
 
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