Led light, seedlings

Morning, i recently brought a small led for my seedling tent ’ replacing my t5’ they germinated very quickly, sprouted and now seem to have come to an almost stand still whilst still maintaining a nice green colour. My question is how much light should they be getting and does height really cause issues on a unit that you can run a light on 15% or 100%.

@imSICKkid do you have much knowledge on this man? i use cmh so this is my first led.

@kedavra I start my seedling with 50% with led fullspectrum but you can use 100% I do with another seedling cuz I have another plant on my tent with 3weeks old so if you want used 100% or 50% not lest

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@kedavra and if I was you I center all the plant to the light cuz I see space on the center of the light

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i know i have done something wrong, i mean they are healthy just long, tall and not what im use to looking at.

i moved them around just cleaning some things in the tent. They are center again now. only 3 have seedlings the others are just in their still as i can be lazy.

@kedavra yes they look healty

Happy growing bro

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cheers man, thank you very much.


The question of right height/brightness comes up all the time. There is a very simple solution these days. A free or inexpensive app for your phone. They have been shown to give accurate readings. I have an iPhone and use an app called Photone.

Use the PPFD reading from the app. For seedlings you want 200-300 PPFD, once they veg you are looking for between 400-700 PPFD and in flower, 600-800 is ideal.


Man, cheers heaps for this. Im going too look at the apps right now

In other words 24",18"12" light distance lmao

They look like they’re stretching to much so I would lower it a few inches


Cheers heaps man, cant lower that one as it is strapped to the roof. Ill work something out and bring the pots up. I use to just have my t5 sitting on them basically but wasnt sure with the LED

I’m running a cl solar1100 Led. I use that exact same app . Right now light is about 30” off the plants and running right around 1000 reading on my light app. Plants seem to love it . I run 50% red 50% white and 99% blue on my veg cycle . Plants are 3 weeks old grown in soil. Any thoughts ?

Sorry I haven’t gotten back sooner but I’ve been without WiFi.

How many hours a day are you running your lights? The number of hours of light and the brightness of the lamp work together to give you a DLI or daily light interval. The DLI is the important number. The examples I gave above are for a 16/8 light schedule and 12/12 in flower. If you do some other schedule then you’ll have to adjust the PPFD. Do a search on DLI for more information.

In general a PPFD of 1000 is a bit much, but that is just one spot reading. Lights tend to be much brighter directly over the plant and the PPFD falls off as you move to the sides. You need to get the average of the PPFD readings to be in the target DLI. Use your light meter to measure from side to side of your grow space and watch how much it changes.

If the average ppfd reading was 1000 over the entire canopy of the plant that would tend to call for increased feedings to keep up with demands.

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Thanks for the info. The readings fluctuate you are correct 800-1200 . Just doing some experimenting with feedings and lighting. So far they are responding great. I monitor them closely they are my babies . So far all I feed is a compost tea . And water with 6.0 ph water . My ph in soil is running 6.0-6.4 . They are in week 3 of veg cycle and are about 10” high and just as wide . Think I should be using an liquid fertilizers ? Getting ready to scrog them . Thanks in advance for any help.

Almost forgot running lights 18 on 6 off. Today I redid the room and lined each wall with Mylar . Like looking into a mirror now . Also added another fan for air circulation.