Seedlings don't do well when in a window. Right now I have it up 30" from the floor (so 12" from the humidity dome and 28" from the new seedlings ) and I get a stable temp of 79*F under the led in my other dome. I know that LED's can burn seedlings even though they don't put out a lot of heat, so I started out at 56" as per the manfacturers recommendations but quickly realized that's way too far after some reading on here so that only lasted a day. “When can cannabis seedlings be put under lights or in the sun?” is a common and sensible question that is often asked by novice cannabis enthusiasts after germinating seeds indoors under lights.. For those who are growing indoors, cannabis seedlings may be put under lights as soon as they emerge from the soil or growing medium.. How much light for cannabis seedlings? The number after each LED color represents the percentage of that color, e.g., G50+R50 means that plants were grown under 50 percent green light and 50 percent red light. Finally, in flower you will want the plants to have a distance of 1-2 feet from the lights. Figure 1. Once you are in Vegetation, you can lower the LEDs to be around 2-2.5 feet above the tops of the plants. Not Considering the Other Factors. Dimmo Thankfully, adding a grow light is super easy. Starting Seeds Indoors Under Lights February 8th, 2010 by david laferney Leave a reply » Seedlings growing under lights. However, LED lights generate no infrared light and don't emit nearly as much heat, so there is no need for abundant watering. When can I put seedlings under the big light? It can't use all that light when it's a little seedling anyway. I know that LED's can burn seedlings even though they don't put out a lot of heat, so I started out at 56" as per the manfacturers recommendations but quickly realized that's way too far after some reading on here so that only lasted a day. I started ... 72 plants per tray – because I plan to plant out these cold season plants under row covers or in the greenhouse as soon as they are big enough to handle. If not when is the best time to do it please. - posted in Cannabis Propagation: Hi all, I have 5 SLH feminised seedlings in 1.5 litre coco, theyre about 3 days old, and I have them under a small CFL lamp but theyre really reaching for the light. Also, if the seedling is still crooked do i wait to put them under the lights or can I just place them under? Is this a good distance to put the light at or should I get it closer? When in the Seedling stage, you want the light to be around 2.5-3 feet above the tops of your plants. Even the most hardy seedlings have to struggle. Seedlings I’m larger pots take forever to show signs of growth because they are in larger pots, so the waiting game sucks. Anyone confirm or deny this? when can I put seedlings under 600w. Affordable plant lights can be found at many garden supply stores for less than $100. I have 4 Auto seedlings under a 300 watt LED light right now and I guess they are doing okay. Like you, when I just started indoor seed starting, I also had a lot of questions to ask, like 'when do I put my seedlings under light' or “how far my seeds should be from the LED”. Discussion in 'First Time Marijuana Growers' started by millhouse86, Mar 16, 2012. so 12 hours hps, followed by 6 hours cfl, followed by 6 hours darkness would be fine. Many types of seedlings grow super fast, and they will start reaching for the light as soon as they emerge. That's not what you want for starting out a garden. Is it ok to put new seedlings under MH if I leave it up high in the grow space? The distance between the plant and the LED will depend on the light you're using. The more you know or are able to apply to your gardening, the best your plants turn out at the end of the day. The LED Grow Light must be used properly for optimum growth and yield. as long as there is no darkness interval between putting them under different lights, and there is still the reccomended dark period, this should be fine. I've since lowered the light to … How to Use LED Grow Lights 2019. Add a simple timer, which will turn the light on and off automatically, to make a simple but effective growing system. Seedlings need more light than full grown plants, ideally as much as 16-18 hours a day. I have 4 Auto seedlings under a 300 watt LED light right now and I guess they are doing okay. The most common mistakes with LEDs are not having enough light and not placing the light at the proper distance.If you do not provide enough light, your plants will not grow to their full potential. Here are 10 things you should avoid doing when using LED and other types of grow lights. The answer to this one is simple. Q: Last spring I had lots of luck starting seed of coleus, impatiens, zinnias, marigolds, and vinca with just one fluorescent light.I want to add more this year, and I'd like to know which lights are best. And yes, as the dude above said, you can of course switch to your LED.