I recently got a full spectrum grow light that I'll mainly use for my seedlings and to give my herbs and veggies a head start. But I'm struggling to figure out the right intensity of light for them. I know PAR and PPFD are the best measures for plant usable light, but those PAR meters can be pricey. I've also read that LUX can serve as a rough reference. I'm not after exact numbers, just want to avoid over or under-lighting my plants. My grow light provides about 5000 LUX at 10% and up to 50,000 LUX at 100%, and I'm running it for 16 hours a day. Since my seedlings have started looking a bit pale, I'm curious if I might be giving them too much light? Are there any general LUX guidelines, considering different plants have different needs?
1 Answer
If your seedlings are looking pale, it could be due to a nitrogen deficiency, not just light intensity. You might want to give them a light feeding of nitrogen-rich fertilizer to help them out. Just a thought!
I was thinking the same! But my seedlings are still pretty young, just at the cotyledon stage with maybe one set of true leaves. I'm using a John Innes Seed mix, so I wasn't sure if I should be fertilizing yet.