Nute or light burn? & nutrient question (seedling)

Hi, I have 3 seedlings here in coco/perlite, 2 critical orange punch & 1 charlottes angel cbd all by Dutch passion. They are in solo cups under a 500w LED running at about 10% power currently, it was running at 60% veg and 40% bloom when they first broke the surface but I turned it down after seedlings health declined.

3 days into them sprouting I noticed signs of some issues with all 3 seedlings. One of the criticals first set of true leaves began to fade to grey at the tips. The other critical’s first set of leaves started twist/curl up and turn yellow. The CBD seedlings leaves are basically shriveling up and I have been unable to see any new growth for around 3-4 days.

I did however test the pH of the runoff of my medium to find it was at 6.8 for all plants which I have now lowered to 6.0-6.2 and am continuing to lower. Also when I buffered the coco I only had enough for a half dose of calmag.

Critical that faded to grey

Critical that faded to yellow

CBD seedling

So basically my questions are:
- is that light burn or nute burn on the cotyledons?
- could any of the issues be due to too much light?
- Due to the stunted growth, should I continue to feed seedling strength nutes until they develop? They’re 1 week old today
- does the CBD seedling look like it will die? It has not changed for days
- how high should my light be hanging above the seedlings and at what intensity? (Viparspectra par1200)

sorry for the long read, just trying to get on top of them. Temps/humidity/air flow is all good and lights run 18/6. Thanks

they don't need any nutes for the first couple of days, then you should be feeding something like 1/4 strength. how much are you watering and how frequently?

blurple lights can be hung pretty close, but blurple lights have also been known to produce the strange growth patterns (twisting etc.) you describe. Light bleaching is your concern with these LEDs getting too close. check the LED forums for brand specific info.

For nutrients I’m using GH flora trio and calimagic, initially I was feeding each plant up to 100ml of 1/4 strength once a day.
3 days ago I lowered that amount to about 20ml per plant a day. I also started pHing feeds to 5.6 to lower the pH of the medium to 5.8.

When they're this small, you don't have to water them daily, you just need to be sure the coco stays moist.

They're little, they don't need huge amounts of light, but they do need light...just use common sense. Once they get up and running you can hammer them with light.

Your coco looks broken down or as though it has something else in it? Can you elaborate on the brand? Did you buffer it?

Keep your feed at 25% strength for a week more, pH 5.8...keep the coco moist, but don't get hung up on daily feeds...they will come with time. In a week bump them up to 50%, following week 75%, etc....which is consequently a little slow in terms of getting them going, but they'll need a little help (you being patient) to get going full song.

Always make sure their feed (water) has something in it nutrient wise...no plain water. And don't let your coco dry out.

Good luck.

CannaCountry said:

When they're this small, you don't have to water them daily, you just need to be sure the coco stays moist.

They're little, they don't need huge amounts of light, but they do need light...just use common sense. Once they get up and running you can hammer them with light.

Your coco looks broken down or as though it has something else in it? Can you elaborate on the brand? Did you buffer it?

Keep your feed at 25% strength for a week more, pH 5.8...keep the coco moist, but don't get hung up on daily feeds...they will come with time. In a week bump them up to 50%, following week 75%, etc....which is consequently a little slow in terms of getting them going, but they'll need a little help (you being patient) to get going full song.

Always make sure their feed (water) has something in it nutrient wise...no plain water. And don't let your coco dry out.

Good luck.

Click to expand...

The coco is just a cheap brick bought from my local garden store, I didn’t get the brand but it wasn’t anything good. I did wash and buffered half strength as it was the last of my cal mag
Thanks for the reply