LED light distance from seedling?

Strain; White Widow fem
Soil in pots

System type na
PH of runoff or solution in reservoir? Na

What is strength of nutrient mix? Not yet determined

Light system, size? (2) LED 450 W switchable,dimmable
Temps; Not yet known, some control
Humidity; Not yet known, some control
Ventilation system; Yes, 400cfm, forced outside air.


Co2; No

Sorry if this has been answered before. First post, first grow, waiting on seeds. Will have max 3 plants. How far should these lights be from the seedlings? All I’ve my previous attempts from bag seed (many years ago) grew skinny and fell over. I want strong healthy babies. Thanks.


First let me welcome you to the forum @Nod
All good
Start your lights 24 -36 inches above seedlings and lower them if the plants start to streach to much
Sprouts dont need a lot of light to start so ine fixture is probably enough to start seeds with
I would do a test run before you get your seeds and test out the set up
Youll want to leave exhaust fan running 24-7 as well as a fan to circulate air in room or tent


John gave you good advice. I use led’s and start about 18" over the soil level and lower them as they grow. It will depend as well on the intensity of the light being used as well. Just watch for any indication of stretching or light bleaching as those are the two extremes.

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This is from a 450w meizhi led light… Maybe will help you


Thanks. Your ventilation comment brings up another question. Ok to ask here or should I do another ticket or go to another category?

This is your thread now so ask any questions you want @Nod
Tour in luck as well im a commercial HVAC mechanic so Ventilation is kinda my thing lol
Tag me by putting @ symbol in front of my user name like i did to yours above tbis way i onow you directing a question at me or just ask youll get the help you need

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Thank you sirs @Countryboyjvd1971, @Myfriendis410 , @Ron330 , @TDubWilly , @Dieselgrower @Greasemonkey After advice, my ventilation scheme will include a passive intake of outside air into an inlet near the floor of my room and an active exhaust (450cfm) near the ceiling. I will use at least one oscillating fan inside. My led enclosures have two fans each.
I saw that someone had provided a sketch showing their ventilation devices on the same time schedule as their lights and wanted to get some input about that method.
I have questions about other environmental controls, temp, and humidity, as I would like to extend my season as long as possible. With outside air circulation I will essentially be at the mercy of my geography. I live in a region of fault mild winters but it can be wicked dry air. The spring and summers are wet and huuuuuumid. I have a humidifier and de-humidifier and a small space heater, all manual control unless timers are used.
For my first grow I expect to have no more than three autoflowers. My space is a 10’ long by 4’ wide by 7’ high concrete block room inside a concrete block basement with the actual grow area about 5x4.


I personally leave all my fans running 24-7 @Nod
Air flow is key to preventing white powdery mold indoors
Also a high humidity situation during flowering can cause bud rot
Not much you can do about that outdoors but indoors it can be prevented by maintaining good air flow and proper humidity and temp ranges :+1:


Besides the humidity a basement is an idea space for a grow area. Sounds like you will b ok with what you have for the time being. Only time will tell as far as environment.

I got my led light about 22 inches from my seedling. Not throwing ilgm under the bus, but I got a 5 pack of California Dream feminized and only one popped. So it’s the one under the led light now. Claire said my replacement seeds would be on there way. Thank you Claire!!!