Seedlings under LED's


How old should a seedling be before i put it under a 300 Watt LED?


I grow hydro and seed in rooters… once the roots are out of the bottom of the rooters, I throw them in a cloner until the roots are long enough for their individual buckets. I put them in the cloner under a “1500w” (260w consumption) KingPlus blurple panel. I keep it at 4’ from them, and they are covered in domes until they don’t require top feeding anymore. The only thing I don’t like about using the blurple panel for my seedlings is the node spacing - it creates really tight nodes and that’s not always what I want.


thanks for your info BUT that really is no help to me.


lol - I think you can put them under the LED whenever you want as long as the LED is far enough away from them. Start with 4’ and adjust if you see any issues.


THANKS. that’s better info


I’ve had my seedlings under my led since they went in the soil if that helps at all you should be fine


I’ve done 2 grows under leds seed to harvest. I found the “sweet” spot for me is 18" to 24" above the tops of my plants. I start them under 300 watters (125 actual) and switch to 600s (265 watt actual) later in veg and into flower. Set my lights at 24" and let the plants grow up to them. I do some tweaking with height depending on strain but generally 18 to 24 is where I land.


Right from the rip…i have lots of plants grown under LEDs. If your gonna run above 24" watch for stretching. @SilentHippie is right on 18"-24" is about right. I even drop to 12" late in flower alot but feel your ladies out by dropping slowly and watching how they respond. The line between close and too close will be different from brand to brand. And if it has UV that also will play a factor. I hope your question has already been answered if not i hope this helps


@monsterblackbass I have a 300 with IR. In what way does IR play a factor? Mine has 2 IR leds. Still have my seedling under cfl’s till I reach veg but need all the info I can before I switch to led.


If it came with instructions or a guide I would start with that height and move light closer as plants react. I’ve been playing with viparspectra 300ws and my plants seem to like it around the 20" mark for veg then 12"-15" during veg. I’m new to growing and don’t have to many grows behind me but haven’t had any problems as far as lighting goes (besides cooking some plants with having them to close) good luck mate :slight_smile:


Sorry, i meant UV.


This is a great question. I too am just starting and want to know if I just only have a viparspectra 600ws will that hurt my seedlings?


That’s a BIG light for seedlings. I would get a separate T5 fixture or some CFLs in reflectors for your seedlings.


Thank you, for five plants in a 3x3x63 grow tent how many lamps should I use?


I started my last Batch under my leds 300 watt for 5-6 my 600 watt I started 20


How many do you have and with that size you will need a bigger space with 5 plants


I’m going to buy the lamps now. If I had two of this size tents will it work?


That will definitely help


I use meizhe leds 300 with a true 192 watt I use 1 per plant I Recently changed to a 630 watt CMH with 3100 K Phillips lightbulbs


Thanks for that. However, I couldn’t find one of those. I did find a Utilitech CFL 300W replacement using only 65W with 4200 lumens. Is this sufficient?