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**Smokesteve** · 10-11-2019, 10:50 AM

One thing I know is that 3000k will make you plants taller with more spacing between branches.

**Farmall** · 10-11-2019, 12:13 PM

So this is an example : after germinated seedlings are in the pots, utilize a light source of 100W CFL 6500 degrees of color temp to shine on your seedling for about 3 weeks. They can be set above the leaves by 3" or so. After that, switch to your regular lighting set up .Since its LED..hang it about 30" above the cups and monitor daily for adverse effects like light burn..NOT HEAT BURN...Light Burn usually indicated by the tips of the leaf starting to brown out usually 1/8" from the tip.

The CFL's ( a 4 pack at Home Depot is about $9) will start the plants being short and squatty and thick.. Not tall and spindly

You can get a SPIDER outlet to use 4, 5 6 or even 7 CFL's to accommodate a circle of cups with as many as12 -14 cups in a circle with the spider suspended overhead

Homework: https://www.growweedeasy.com/led-gro...-cannabis-buds

**D.A.A.S.69** · 10-11-2019, 12:16 PM

GoodMorning static ,that's a mighty strong light, you've got there!!
Seedlings don't need much light at all, I normally use cfls, for the first week or two, and I try to keep them about 2inches away from the plants.
If I had your light, I'd hang it way up there, 3-4feet, away, and if they start stretching, I'd bring it a little closer, constantly, until you find the right spot.
What does your instructions say that came with your light?
When they start flowering, is when you want it, wide open, or full power.
Seedlings don't want, or need much light,.
That's a nice light, you've got.
GoodLuck
HappyGrowing.

**az2000** · 10-11-2019, 12:20 PM

As mentioned, they like cooler light (in the 6000k 6500k range. But, the best veg lights I've used was a blurple LED. That created some very nice, tight, compact plants for a 4' tall tent. You'd see all that red and think it's not good for veg. But, the blues were enough to satisfy the plants.).

I'm growing two plants under ordinary household LED lightbulbs. I used 5000k "daylight" bulbs (the typical bulbs from the store) and they were still a little stretchy unless I put the light very close. Basically, I had to drive them hard with that color temperature. I was on the border of too much light. If I had used "cool" (6000-6500), I could have used less intensity.

I've never tried to veg under 3000k. I think it would just be more of what I experience with 5000k. You probably have to put the light very close. But, also risk driving them too hard.

If I were you, I'd go buy some inexpensive 5000k at the local Home Depot (or 6000-6500k online. But, you're needs are more urgent.). Get the kind with the base. There are newer LED lightbulbs that are like the old incandescent. They have a froted glass or plastic globe which goes all the way to the threads. You don't want that kind. It has "filaments" suspended in the bulb. You want the more common (over the past 5 years) LED lightbulb with the obvious base which runs halfway up the bulb. Like this Philips 15w (100w equiv) and 8.5w (60w equiv) shown side by side:

You want the LEDs to be surface mounted like that. Cut the diffusion globe off with a hacksaw, and you have instant directional light (no reflector needed. But, a reflector does help a little. But, not nearly as much as CFLs need to be reflected. The difference between unreflected LED lightbulb an CFL is 250% more light reaching the plant.). It's really a huge amount of light for the money. The only significant downside is that you expose electrical surfaces. You should use a GFCI outlet to power these. But, technically, that should be used to power everything in a grow tent.

These can be challenging to mount, aim, position. I can talk to you more about that if you want to go this route. I think these lights make excellent supplemental lighting. For example, I grow with CMH in a 4x4 tent, and use household LED lightbulbs to supplement around the perimeter. I use T5HO in a 4' tall 2x4 tent, and will add some of these in late flower to boost performance. I think they're great tools to have in your tool chest.

I made some different mounts for them. I can give you that info if that's the way you want to go. For example, I mount them on tent legs:

Those are actually the seedlings I mentioned above, and I'm driving them with more light intensity than I should have to, because the light isn't cool enough in color.

Finally, you can spend $20 USD on a Lux meter. (I have a Sunche HS1010.). That's a good way to sanity check your intensity. Since you're using white (full spectrum) light, a Lux meter is good enough. Lux isn't as useful comparing blurple, and HPS, etc. But, for comparing white light designated in color temperature, it's all fairly comparable.

I have a PAR meter too (Apogee 500). I'm finding that the conversion from Lux to PAR is about 50-55 lux per one PPFD. I.e., seedlings should have 200-300ppfd. That's about 13,200 lux. For $20, that's probably useful if you're concerned about intensity. (I'm not in love with the meter I have. I might prefer one with a detachable probe. But, I don't know how accurate the different lux meters are; how comparable they are. I can't guarantee that my 50-55 to 1 conversion applies to other Lux meters.

**Farmall** · 10-11-2019, 12:29 PM

AZ2000.... I love your articulated arm for the light support. I made this similar thing to hold an iPad in a recliner... I see we may both be a bit ….( never mind)

**SoOrbudgal** · 10-11-2019, 12:52 PM

Absolutely wonderful innovation with light source

**az2000** · 10-11-2019, 12:52 PM

Originally posted by Farmall View Post

AZ2000.... I love your articulated arm for the light support. I made this similar thing to hold an iPad in a recliner... I see we may both be a bit ….( never mind)

These mounting things are one downside to using LED lightbulbs. There is some effort/creativity involved beyond just going to the store and buying lightbulbs. But, once the mounting/aiming etc is put togther, it's like tools in a tool chest. Stuff that can be used when needed. Save the grow-light fixture's lifespan for flowering; veg with lightbulbs that cost $15 cents per watt to buy/replace.

I got that idea (for the flexible arm) from the tent-leg mounts I made 5-6 years ago:

And, a top-mount "fixture" I made back then:

I combined the flexible arm from that top-light fixture with the tent-leg sliding mount.

BTW: That's the plant I grew entirely under household LED lightbulbs. It flowered at 20-22w/sq ft. This was the harvest from that plant:

The only thing I noticed is that they weren't very frosty. I think that's due to the LED lightbulbs not having a lot of UV. But, they very potent. I don't know anyone who would have complained.

So, household LED lightbulbs will definitely veg (if it will do that at 20w/sq ft in flower). You don't typically need great lighting for veg. It's flower when a light may disappoint.

There's another example (the two seedlings above, are now these two plants yesterday):

That was Day 60 from breaking ground. And, 3 weeks + 4 days since switching to 12/12. I've been running 25w/sq ft up to this point in flower, and just bumped it up to 28/w sq ft. I've got two more 9w (60w-equiv) lightbulbs to add. That will make it about 32w/sq ft when they finish. (Running stronger light this time. I usually stay down around 22w/sq ft. It's diminishing returns as you add more.).

Those are small plants in 1gal containers. I have white posterboard covering the top of the container because I like to reflect the light back up into the canopy. Plus, the cactus mix is drying too fast for my tastes. This slows it down a little, keeps it more uniformly moist near the top.

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**gbauto** · 10-12-2019, 12:04 AM

Originally posted by static View Post

Hi all, newbie here who has unfortunately stretched his seedlings. I moved them out of jiffy's last night and into my actual supersoil mixture to correct some of the stretch and also bend the stems nice and straight again. Being told to add more soil now as well.

But my question actually is, I'm having a hard time understanding basically how bright my light should be. It's a 480watt LED light, specs here https://www.hydrotekhydroponics.com/...d-panel-107100

and it has a huge range from 0 to 100% basically, and I don't know if I should be on the lower end, higher end, or what. Is there ever a time in this grow where I'd crank this thing to 100% ? Flowering?

And then also how close to my lights should I be putting these seedlings.. should I put them even closer still? There's still a considerable gap between them

Thanks for hearing me out! and in advance for any help!

cheers!

Hi, static.
I didn't see mention of how large your grow space is. That fixture should provide enough output to flower a 4x4 space really well at max power. That will give you approx. 30w/sq ft of area during flower. I veg my plants at about 15-20w/sq ft. The recommended hanging height of 18-24" is what I would use to give you good uniformity across the space. Good luck with the grow.

**MLDGrower** · 10-12-2019, 12:30 AM

First time grower here. I've ordered the gear and seeds, and I will start growing soon.

I will be running a Bestva 1500w dc series led in a 4x4 tent. Any suggestions for supplementing my light for either vege, bloom, or both?

**homegrown** · 10-12-2019, 01:13 AM

hey static, i dont know anything about your light but if its dimmable, I would turn the light intencity down and lower the light fixture. Not too low..its better to start slow and see how the seedlings react. When their that small they dont like strong light.

**dphipps1020** · 10-12-2019, 12:09 PM

So I just looked at your link for your light. Recommendations say 18-24". I would go higher than that for seedlings, maybe double to start. I just got new lights too and I'm doing the same as someone else already mentioned and just inching it down. I have 3 currently running in my 8x8' tent (1200 Watt equivalent, not sure the brand) and will be adding a 4th for flowering. So far they're great. Started these from seed but had my lights about 3.5-4' up to start, I've lowered them since. I actually use a couple of flat panel LEDs for my seedlings and they work really well (45W equivalent, 15W actual I think).

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Newbie having trouble understanding LED intensity levels, and distance from plant

SOIL Newbie having trouble understanding LED intensity levels, and distance from plant

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