Another help me design my light setup thread :)

[Rama777]

Okay so I have a 3x3 that I’m running HPS with. I want to switch to LED but also be able to grow with them in the winter.

Lung room gets down to 64 degrees and humidity is high. Preserving heat by reducing extraction is not an option. I need heavy exhaust.

With the 600 watt HPS even with the low temps it’s still a bit annoying to keep the temps right. I get 82 at canopy and it’s more like 72-73 degrees below canopy.

The Vivarspectra KS3000 seems to be the best bang for the buck, but it’s only 350 watts. Not enough heat with my heavy exhaust.

So I’m thinking about either two HLG 260 or 300 rspec lights. That would be 520-600 watts. Plenty of heat for the top half of the room.

Other option is the KS3000 above, but with supplemental side lighting down below. I feel like that would probably be better for yields, but also raise the temperature enough for the lower portion of the room.

I could even put a 100 watt light panel in the center facing up, but that seems tricker than side lighting. Hell I could do all of it, up-facing lights and/or side lights with the KS3000, or 520-600 watts from 2x hlg lights? Or shit, two HLG’s dimmed as needed AND side lights?

What would THCF’s do?

 

[LoveGrowingIt]

Did I read that right? Are you really thinking of running 600 watts in a 3x3?

 

[Rama777]

Yes lol, but I would factor into the grow how much distance would be necessary between the canopy and the light of course. Heat is what I’m after, while also being able to run LED’s.

HPS is in the tent right now. If I had a KS3000 in there instead, I’m pretty certain the temperature would be like 70 degrees at canopy and in the mid 60’s below. So yeah, I can keep running the HPS in the winter. That is certainly an option, but if I can find a way to do it with LED, all the better.

I have seen some journals of someone running 550 watts of HLG PLUS supplemental lighting in a 3x3. But, I don’t think he pushed much beyond 440 watts. One way or the other I would like to be pushing probably 450-500 watts at the coldest times. Just not quite sure how I’m gonna go about it.

 

[crimsonecho]

sounds to me that hid is perfectly suited for your grow environment why switch to leds even?

 

[HerbalEdu]

don't expect 600 W led to produce as much heat as 600W HPS ...

 

[Rama777]

Good question. They won’t at all be suited to growing under at any time other than the winter. So I definitely do need LED’s at least for most of the year. If there’s a viable way to set the tent up with LED’s for year ‘round purposes, I figure that’s the route I should take. Plus, sometimes the HPS tent gets TOO hot. I feel like LED’s have the potential to give me more control at all times of the year.

 

[Rama777]

don't expect 600 W led to produce as much heat as 600W HPS ...

Cool thanks. Well, I don’t hardly ever need all of the heat. To be honest a 400 watt HPS would be just right, probably with side lighting, but the extra lumens from the 600 watt are worth the hassle of adjusting things daily to make it work.

 

[LoveGrowingIt]

Yes lol, but I would factor into the grow how much distance would be necessary between the canopy and the light of course. Heat is what I’m after, while also being able to run LED’s.

How about a heater in the tent? That's what I use.

I think most LEDs are recommended to be 18 to 36 inches above the canopy. Most tents are maybe 72 inches in height. 36 inches is half the tent height, so it's not a practical distance. Subtracting the height of the pot leaves little vertical space.

HPS is in the tent right now. If I had a KS3000 in there instead, I’m pretty certain the temperature would be like 70 degrees at canopy and in the mid 60’s below. So yeah, I can keep running the HPS in the winter. That is certainly an option, but if I can find a way to do it with LED, all the better.

One of the often-stated advantages of LED lights is their low heat signature.

I have seen some journals of someone running 550 watts of HLG PLUS supplemental lighting in a 3x3. But, I don’t think he pushed much beyond 440 watts. One way or the other I would like to be pushing probably 450-500 watts at the coldest times. Just not quite sure how I’m gonna go about it.

Well... I wouldn't rely on lights to heat the tent. For one thing, most of the heat from the lights goes to the top of the tent.

Here's a picture of my 28"x28" tent. There's a 130-watt AC Infinity T22 at the top that I haven't used yet. The seedlings are getting started in my other tent. I have an oil heater at the bottom. I like those because they provide consistent amount of heat. This one dries out the pot because it's too close. I'll probably change to a different type of heater. I also didn't realize that new humidifer would be so big, so it might move to the bigger tent.

I had a 240-watt light in this tent. The most power I ever used was 135 watts. So the 130-watt should do okay.

The saucer and trivet for the pot are sitting on a turntable. I started using a turntable during my last grow. It seemed to work out well. I turned it about a quarter of a turn every day. That's when I noticed the heater was drying out the soil in the pot. My main goal was to balance the light the plant was getting.

 

[Rama777]

Thanks for the insights! I won’t really ever have space for a heater in the tent.

As for the light distance, I’m still trying to find out what the drawbacks are of dimming the light if things get a bit too close for comfort.

Captain mentioned that the spectrum can be incorrect when not driven at 100% in flower. HLG has a webpage that claims that dimming their lights during flower does not alter the spectrum enough to be meaningful. So yeah, 36” distance would be no bueno, but using the dimmer to get closer? Questions questions..

 

[crimsonecho]

whatever calculations and planning you do, to get temps similar to hid with led you have to run a dedicated heating component in there. there is no way to reach hid levels of heat without bleaching your plants with leds. 3x3 300w is perfect anything above will cause more problems than benefits. over under sides it doesnt matter that much.

 

[Rama777]

whatever calculations and planning you do, to get temps similar to hid with led you have to run a dedicated heating component in there. there is no way to reach hid levels of heat without bleaching your plants with leds. 3x3 300w is perfect anything above will cause more problems than benefits. over under sides it doesnt matter that much.

You maybe right. I’m not attached to anything yet. Also, another important factor is leaf surface temperature. With the wasted energy of the HPS, it increases the LST over LED’s.
So 76 degrees in a tent with HPS versus LED is going to create warmer leaf temperatures.

Also to be clear, the HPS is in an air cooled hood with a 6” exhaust fan set to 8 most of the time. So I’m definitely managing too much heat.. HPS? Too much heat? 350 watt LED? Probably too little. Just exploring if a happy medium can be achieved somehow while not having to make up for it with the HVAC system too much.

 

[Rama777]

I wish I could talk to this guy but apparently he dropped off the map. Master grower with 30 years experience. This is in his 3x3 tent. That’s 910 watts of lighting. I’m not gonna do this or anything and I’m not a master grower.

I will say he did end up moving to just using 650 watts of lights installed and he never ran everything at 100%. And just because he’s a master grower doesn’t mean this was the greatest or most logical l3x3 light setup ever. But, damned if he didn’t pull 28 ounces of buds from healthy plants when he had all 910 watts installed.

 

[Rama777]

Oh and his lung room was usually 65 degrees for that grow which happens to be about what mine gets to.

 

[crimsonecho]

I wish I could talk to this guy but apparently he dropped off the map. Master grower with 30 years experience. This is in his 3x3 tent. That’s 910 watts of lighting. I’m not gonna do this or anything and I’m not a master grower.

I will say he did end up moving to just using 650 watts of lights installed and he never ran everything at 100%. And just because he’s a master grower doesn’t mean this was the greatest or most logical l3x3 light setup ever. But, damned if he didn’t pull 28 ounces of buds from healthy plants when he had all 910 watts installed.

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if he never ran everything at 100% then does it really matter how many watts he put in the tent. one suggestion i might make is to add ir lights then. run 300w of leds as a baseline and see your temps and close the difference by throwing some ir bulbs or ir tubes maybe. whichever is available. in the end thats whats missing in leds compared to hid and really over a certain level you cant push the plants anymore without getting bleaching or burn or serious foxtailing later in flower.

 

[Rama777]

IR bulb great idea!

 

[crimsonecho]

IR bulb great idea!

not surprised tbh i’m full of great ideas lmao

keep us updated i want to see if you implement this idea and how it works out. also dont go overboard with this one because too much ir cant be good either. i’d start with the smallest bulb i could find and add more if needed.

 

[Rama777]

Totally..

I have some time to keep researching. I’m leaving towards a single 550 watt HLG rspec V2 plus 4 AC infinity 16” supplemental bars for the far ends. That allegedly could give me 1,000 ppfd at the center and 900 at the corners at 24” high from the canopy running somewhere at around 450 watts. Also this setup would negate having to frequently adjust the distance with something like a vivarspectra ks3000. Sure it would be less energy efficient. But 18-22 extra bucks a months is probably worth the time saved adjusting the lights up and down. I am insanely busy with running a produce farm. But then yeah, we’ll see what’s up with the temperatures with that setup if that’s what I get..

 

[LoveGrowingIt]

So yeah, 36” distance would be no bueno, but using the dimmer to get closer? Questions questions..

There are only two ways to adjust the light intensity—by changing the dimmer and/or the distance.

I only use 36" is for seedlings or veg. My tallest tent is 72 inches. Subtracting from that about 24 inches for the light and the pot leaves 48 inches between the light and the soil. Subtracting another 18 inches as a minimum distance from the light to the canopy leaves 30 inches for the plant. I usually flip when the top of the plant is about 15 inches above the soil, leaving another 15 inches for the stretch. Of course, that's an estimate, and there's some flexibility in those numbers. Nevertheless, I often wish I had a taller tent.

 

[Rama777]

Yeah 72” is pretty short. Mine is 80” and I would have gotten a taller gorilla tent but Amy ceiling height where the tent is was my limiting favorite. Allowing 24” of light distance, plus 8” for hanging the light and 10.5” for the 7 gallon pots leaves me with 38” for the plant. Wish that were 48” but it’s not bad.