Beginner light intensity and distance question

My plants are about 2-3 inches tall in solo cups, and have two leaves each. Here are my lights:

I’m running them side by side. It;s a dimmable light, and will run it 18 on -6 off. I am growing 8 week (supposedly) auto flower Bruce Banner.

What light intensity and what distance to the plants would you recommend for weeks 1-4 ?

Thank you all for watching etc, I’m new obviously.


Tag @dbrn32 ,he’s the light expert here.

What I see are drivers telling me you have two roughly 200 watt lights… that’s all. The driver label is not representative of the light. Even dbrn couldn’t help without more information or pictures.

COPY/PASTE the below list into your forum post.

Answer these simple questions the best you can. If you are not sure, just bring it to our attention. We will figure it out.

Indoor or outdoor? - size of grow?

Origin of seeds?

Regular, feminized, or autoflower?

Origin of water. PH, EC/TDS of source water?

PH and TDS/EC of if mixed solution?

Grow method? Soil, Soil-less, Coco, Hydro, Aquaponics. Please explain.

Nutrients or fertilizer system used.

What typr of lighting are you using? LED, HID (MH, CMH, HPS), or Fluorescents? Please elaborate.

What are the temps in your growspace? Day / Night?

What is the RH = relative humidity in your growspace? Day / Night?

AC, Humidifier, De-humidifier?

Do you have a Ventilation system? Size? 4", 6"?

Co2 Yes / No?

How long have you been growing?

If you grow hydro, then please explain your hydro method. DWC, R-DWC, Ebb and Flow, Or; Other? Other?

16b. Size and temperature of solution in reservoir?

Always try to upload a clear picture in white light of any issues you may have to allow the community to identify your issue.

Anything you feel would help us give you more informed advice should be included. Feel free to elaborate at the end of the survey.


@dbrn32 can verify or correct
10-15% dimmed, about 12-16 inches.


I plan on growing 4 -6 plants maximum

Indoor - 5x5 in a closet in the back room of the house

this websites autoflower bruce banner

Origin of water. PH, EC/TDS of source water? tap water city water

PH and TDS/EC of if mixed solution? no idea

Grow method? 5 gallon bags , soil made of mostly top soil, mushroom compost, peat moss, handful epsom salts handful dr earths organic grow mix 2-2-2 in a 20 gallon tub

Nutrients or fertilizer system used. general hydroponics 7-4-10 and 4-8-7 liquid, in water every few feedings once I get the plants established

What typr of lighting viparsp[ectra xs2000 (x2)

What are the temps in your growspace? Day / Night? lights on about 80, lights out 72 whole house is central air

What is the RH = relative humidity in your growspace? 50% give or take

AC, Humidifier, De-humidifier? hope not, I can control the whole house if I need to, see below.

Do you have a Ventilation system? Size? 4", 6"? will install 4" VIVOSUN 4 Inch 190 CFM Inline Fan with Speed Controller, 4 Inch Carbon Filter and 8 Feet of Ducting, Temperature Humidity Monitor for Grow Tent Ventilation when I figure out how to do that.

Co2 Yes / No? no

How long have you been growing? first ever

Thank you all so very much!

It’s a pocket door into a back closet the whole house is A/C I can open and close the pocket door for temp control, it gets 90 plus if I close the door and leave it (the lights are hot) and have a humidifier if it needs to go up. I have a vent van listed above if I need to install it I can.


Looks like your room could have a lot of potential! I’m not very familiar with the vipar lights you have, but I’ll share what I think will help.

I believe these drivers have a io adjust screw on the bottom. It should be turned all the way up from factory, but not all of them are. For sprouts I typically run lights using hlg-240 at half power about 24" above. Then just watch how plants behave and adjust as necessary.


To add. You’ll only need to use one of them for the time being. They use much less light in veg. Thankfully these leds use less electricity than the lamp my grandparents had in the living room.

4 90 watt incandescent


Just from the driver pics, I’m assuming (2) HLG 300 RSPEC? Any way you said 2-3” tall. An age works better for lighting. 1st 3 weeks after a germ period (10-12 days) If in germ they need humidity and a lesser intense light. I pretty sure the lowest setting on these lights start at 27 watts draw or and I put my run under domes at that setting then dialed it up to 2.5 clicks around 35 watts at 26”. Here are a few light readings I found through some research.

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They are xs2000 from viparspectra (times two)

EDIT I have not a singgle idea what those pictures represent… any explanation would be greatly appreciated.

Thanks all for the input!

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It’s the photone app. Which should be out for Android by now I thought. Long been out for iPhone. It’s long since been beta tested… lol

Well not long since. But we’ve been beta testing for about 2 months, may be out in finished product and I can’t see it, since I am a tester.

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PPFD is the amount of light photons that hit your canopy or surface in 1 second, basically the light strength that hits your plant and should be increased with the growth. DLI is the total amount of light that the plant gets daily, simple terms daily dose of lighting. This is increased as well throughout the grow. For a light meter app @Budz has you covered :love_you_gesture:

It’s 30inchs you have Ur lights away as ur plants grow taller than you drop the distance

And as for how high U should have Ur light turned up I would go 30-40 %

30-40% of what wattage? 100 or 200? How did you come to that %? I didn’t ask the height question, he did. I use a meter and with that I know what height to intensity I need to be at :love_you_gesture:

I would say same as over guy u only need 1 light to germinate and probably for the first 2-3 weeks. I sprouted 3 with a sf-1000 which is 1/4 of ur 2 lights. Followed user manual as a guide, I have a viparspec xs1500 which still less then yours and now at 20 ish inches off top a 80 ish % still hitting all my DLI and PPFD #, used manual and par chart to help guide, post pics when sprout forum is great if they are stretching some one will let u know BTW I’m new too on first grow best of luck

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Ok Here’s a light map of my one light, I have 2 identical. Anyone got any good input? This is 24 inches from the light. Full dim and full light.

dead center and corners of the light.

There is also an app for Android called PPFD. It’s not as accurate as photone and I may or may not have recommended a version of its best feature go into the new photone Android version. Neat little tracking thing the PPFD app does. If you don’t have a smart phone or other way to test lest light intensity you just have to do it the old fashioned way. Listen to the girls. They’ll stretch out nodes if not enough light, the canopy leaves will curl if too much. I’m sure your product manual has recommended hanging heights/power. They almost all do. Which is a good starting point.

First three weeks:

The marijuana crop’s first stage is also its most important. Cultivators should ensure their first-stage canna plants get DLI from 13 – 19 units each day. That’s at a rate of 200 – 300 PPFD for eighteen hours.

At this range, there’s a chance of better yields when your plant crosses to the vegetation stage.

Vegetative stage:

At the veg phase, your plant has to receive upwards of 20 moles of light each day. But the DLI isn’t expected to exceed 35 units at this period. Because this is a make-or-break stage, growers are mostly at odds on numerous fronts.

During the veg phase, canna plants usually require more energy to boost growth potential. Some growers could flat-out disregard recommendations and double the required DLI for increased vegetation.

Several elements, like hours of light, light intensity, and grow light spread could impact growth at this stage.

Flowering stage:

Optimal flowering may require around 38 – 65 DLI units each day. If your marijuana flowers as it should, you can expect a good harvest

These hijacked numbers are obviously for autos. But not really that different.


thank you!!! so, my light needs to be up all the way at 24 inches, for growth until I flower then get closer to the plants when it goes into autoflower. Is that the JIST?

anyone else? dbrn32 any input from the light map made from my ihone?

Basically, yeah. Once you see crowns you are in flower.

Examples of crowns.

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If you don’t have a par meter or any other fancy meter, I’ll go out on the limb and say if you don’t have the manufacturers recommendations, at least 24" at 60% intensity in Veg. That’s Veg! Not seedlings or flower. I’ve recently changed from HLG’s to a Groplanner and both had the same distance in seedling, veg, and flower. Seedlings you’ll have to adjust heights until you dial it in. Not to hard. I run 50% and about 30" for seedlings. Flower will be closer to the lights and that’s when you crank up the intensity to 100%. I run my flower cycle right at 16-18" full power