Hey guys and gals lol. I think I fried my seedling 
this is my second grow and I am a little too excited. What is you all’s opinion on seedlings’ light cycle? Is 24 hour light too much? Should my light be at the least 6ft away? Thank you all in advance and happy growing.
4 Likes
what makes you think you fried them. How old were they? Were they “crispy” or what anyway for my outos they spend week 0 and 1 under t5s then weeks 2 to 4 under t8s at which point there flowering and into the perpetual tents I run normally 20/4 but sometimes 24 need more info
1 Like
I only ask if you are sure it was light burn or heat stress because there could be something else going on that kills seedlings the dreaded and mysterious “Dampening off” silent mass seedling murderer but it’s easy to fix I would need more info to help you
2 Likes
Hey, thanks for replying. The top of my seedling was dark brownish and the stem was very damp. Due to the dark brownish top, I figured I burned them. But then you mentioned the dampening so now I don’t know what may have happened. I have a Mars600 my space isn’t that big one light of that caliber is enough. I appreciate your assistance.
I use 18/6 lighting for seedlings after I plant them.
How far away your light should be definitely depends on what type of light it is. My T5 lights that I use for veggie starts need to be pretty close or my seedlings get leggy. My HLG boards need to be dimmed and much further away.
1 Like
yeah I would look up the light see what the manufacturer says as far as dampening off theres things you can do to eliminate it from your life first it’s pathogenic so always use clean potting mix for seedlings It’s caused by cold wet enviroments say a heat pad seed starter thing always plant near top of whatever there going into for circulation increase airflow keep them warm and probably most important not too wet
3 Likes
i give them 19 hours right from the start until i put them in to flower, that extra hour adds up. i use led lighting and i adjust to the par so i get full use of the spectrums. get good results most times but there are the off times too cause i am trying to recreate an environment inside a tent, so in the end my choice of medicine grows for me
1 Like
Seeds start at 12/12 for me…the males stay at 12/12 so I can collect the pollen & the females gets revegged…
3 Likes
As someone said, get something to help regulate the temp, ease up on the amount of water, and airflow. Happened to me once and I damped off several. Good luck!
1 Like
Thanks for the advice for sure. This is my 2nd grow I’m more excited than the 1st lol.
Give your seedlings the same light you give your vegging plants. Failure to do so results in leggy seedlings that fall over and grow slowly. They can handle full sun if there’s enough moisture, Cannabis is a sun-loving plant. 6ft away is too far for ANY light. Inverse Square Law of lighting.
Not sure where the “no nutes and weak light” advice for seedings came from.
3 Likes
you will get it most importantly avoid cold and wet a seed heat mat works great for this I’ve had much better germ succes using one good
1 Like
my philosophy as well! Seedlings in nature don’t get weakened light, they get full sunlight from day one. When cannabis culitvation guides say use less light for seedlings I think they’re speaking to huge commercial operations that want to use the lowest feasible light level to save on electricity cost.
I use 18/6 or 17/7 with all vegging to mimic nature, 24 hours seems unnatural and stressful. Without a light meter it can be hard to judge how bright the light is. the “back of the hand” test is good - put your hand where the canopy is and try to make the brightness level similar to outside light or your veg/flower rooms.
4 Likes
That’s probably it. People who start like whole multiple trays of seeds inside for OD just use a fluorescent shop lights, or used to. Probably where the idea came from.
I figure if Cannabis seedlings can start day one on a sunny dry mountain in Morocco, they can handle any grow light lol. Sometimes I’ll even raise the seedling tray up higher than the other veg plants, I like a short tough seedling right out of the gate. Less likely to get damp off and shit too. Mine are about 2’ away from a CMH bulb and they thrive, I have never burned a seedling with light.
I feel like 24/0 is a good policy if you have weaker light source. 18/6 is better if you have stronger light. By the end of the 18hr cycle in my veg tent most plants look like they could use a break, done with photosynthesis for the day.
4 Likes
I recently splurged on the Apogee light meter - if you have a spare $400 lying around it’s a great toy!! The light level in my tents & closet was around 300-700 umol/m2/s - I got a surprise when I took it outside on a sunny day in May - 1100! That was an eye-opener. So really any cannabis plant inside should be able to take 1100 umol/s/m. I live at 43 degrees north too - further south the outdoor light is well above 1000 umol/m/s. I’ve added more light to my flowering tents to get closer to 1000.
5 Likes