220W LED light distance for seedlings

I’m a new grower and have a 3’x3’x6’ grow tent with air circulation system and a 220W full cycle LED light. I plan on soaking the seeds in water for 24 hours and then planting in seeds in potting soil. I was thinking that I would put the small pots in the tent under a clear dome and the light on a 18 hour on 6 hour off cycle. The manufacturer says the light should be at about 4 feet above the plants in the veg stage so I thought I would start there. I’ll keep the temp around 72 degrees F. Any thoughts or advice? Thanks

4 feet is a little far, but not for seedlings. As they become more established you can slowly lower the light. @Hal and welcome to the forum. The other thing to consider is the actual watts used. Depending on how many seeds you start, you probably need more lighting. If you purchased it from amazon, amazon links are allowed.


If you haven’t dropped seeds yet, can we ask a few questions to help you get the best bang for your buck on your first grow?

With your tent you can probably grow two photoperiod feminized plants, but you could easily just go with one as well. If you are growing autos, then two or three would be appropriate for that size tent. For a first time grower I would strongly encourage you to NOT make the same mistake I made, which was growing too many plants at once. Just grow one or two.

So all that being said, what strain and type are you going to grow? Do you already have a plan for transplanting your plants when the time comes?

For your light - can you tell us the brand and model?


Thank you for your fast response. I plan on only 2 plants. The light is a Lightworks Solarstorm 220. The spec sheet says that it will cover a 5’x5’ area during veg stage and a 2’x2’ area for flower stage. The spec sheet also contains these specs:
@ 12 inches 1773 lumens
@ 18 inches 745 lumens
@ 24 inches 420 lumens

I have not started the seeds as yet. I am planting White Widow feminized seeds. I plan to transplant into Fox Farm Ocean when ready. I also have Fox Farm nutrients to be used as directed.


Looks good! That 2x2 area for flower is something to consider when the time comes. I’ll let light expert @dbrn32 chime in, but it might not be a bad idea to plan on purchasing a second light when the time comes.

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California lightworks specs their lights in lumens? I will have to go look. Be back shortly

Here you go, those numbers are photosynthetic photon flux density measured in umols. Way different than lumens.

It looks like that light is available in different spectrums. Do you know which version you have?

Can’t use like function amigo, appreciate the tag.


Sorry for the tardy reply. I have a Full Spectrum Lightworks Solarstorm 220. Thanks


No worries, I figured as much and that is the model I took screenshot of above.

It lists 420 umols at 24”, which is considered optimal for vegging plants. Optimal means you could probably run it higher and provide enough light with a bigger footprint if need be. But I would think 48” above pots would be pushing it. Maybe 48” off the floor with a pot that’s a foot tall. Most of us would refer to that as 36” as we generally site distance above canopy to eliminate any discrepancies in pot height. I’d look to start seeds around that height.

From there you’ll pretty much just watch for stretch until you get a couple sets of true leaves. If you see the plant start to get tall quickly, lower the light some. Otherwise, that’s the point when you’ll start to gradually lower the light. 2” every 5-7 days is probably reasonable. Could be more or less depending on all the variables. This process is usually referred to as light hardening your plants. It will let you run light closer than if you were just to lower it a large amount at one time. For general purposes, you shouldn’t need that light any closer than 24” while on an 18 hour light cycle, or vegging your plants.

Once you decide to flip to flower, or go to a 12 hour light cycle, you can again start to gradually close that gap. I would say 18” or so is about as close to your canopy you’ll want for flower. That should put you about right in the middle of ideal light for flowering stage.

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