Hey everyone! I'm hoping to get some advice on an issue I'm having with my Asian greens seedlings. They seem to be developing bleached leaves, and I'm not sure what's causing it. I have a 128-cell tray set up under four 2-foot long 5000k 144w T8 full spectrum lights. I'm watering them from below, and aside from the leaf discoloration, they look healthy, though their growth seems a bit slow. I was initially keeping the lights about an inch above the seedlings, but now they're positioned about 5 inches away. I'm starting to wonder if they might be getting too much light. Any thoughts or suggestions? I can provide a picture if needed!
4 Answers
You've got a lot of info, but how many hours are your lights on each day? It sounds like they could be getting too much direct light if they're on for too long. I usually keep mine about 17 hours, which might be pushing it for seedlings.
Definitely need to see those photos! It’s tough to give advice without knowing exactly how bad the bleaching is or how everything is set up. Sharing a picture would really help—kind of like how a doctor needs to see your rash!
144w at an inch does seem a bit close for those lights. I use a lower wattage for better heat management and keep the lights higher up. Just a suggestion to try adjusting the distance a bit!
It's normal for the seed leaves (cotyledons) to fade and eventually die off, but since you mentioned the true leaves are also looking bleached, that’s concerning. Make sure to check how the true leaves are looking, as they should be the focus. Also, it might help to share a picture so we can see how they're doing!
Yeah, true leaves are definitely more important. If they're suffering too, that means something's off.
Thanks! I run mine for about 16-18 hours too, but I’m careful about the distance from the lights.