The more details you share, the better the diagnosis.
Don’t worry if you don’t have everything — just include what you can.
What’s the issue?
My seedlings are pretty healthy at 21 days - using Happy Frog or Coco Loco.
Started about 6 varieties. Most with no issues, but some them have strange leaf edges. Some of the seeds that I started in pure Coco Loco have strange discolored edges.
Most my seedlings I’m very happy with.
Grow details (if known):
Strain: various photos
Stage (seedling/):
Medium (happy frog/coco loco):
Light (100W cheap Vivosun LED):
Environment (75-77 ambient, low NM humidity):
Photos:
That looks a lot like variegation (I think that is the right word) with is a “normal” genetic variation that happens from time to time.
Disagree. That’s calcium def
Curious how much cal/mag you’re feeding. And how often.
Also wonder how close the lights are to the top of your canopy?
These specifically are showing because coco sequesters Ca and require more calmag.
@Growdoc @dbrn32 @Dman1969
That’s a freaking awesome looking plant, @Budbrother !
I never had a veriegation. Any changes in growth behavior or life cycle?
Most will only show a couple of leaves and will usually grow out of it. That plant came up in a search and truly shows full variegation. That one wouldn’t process as much chlorophyll energy and have airy buds. Shoulda been culled early showing full blown mutation. It does look cool though.
Thanks for the tag 
@Budbrother.
@maynardg i grow in Coco and you need at least 5ml per gallon. And hungry ones like your showing could use 10 ml per gallon. I use calmag from start to finish. And I feed from start to finish. Coco has no nutrients in it. And your coco needs calmag for nutrient delivery. So pretty much half your calmag is going to to the coco and the other is going to the plant.
Happy Growin
You have deep knowledge, Mr Brother.
Ultimate respect.
Thanks for the tag @Budbrother , I just got here and see @Dman1969 had your back. Only thing I would add is a bit of why it needs more. The cation exchange sites on coco grab on to calcium and give off potassium in exchange, so coco grown plants need enough calcium to overcome the hungry cation sites, plus supply the plant with its need for it. I’ve even started adding cal mag to every feed this grow in Promix, I’ve had zero deficiency of any kind.
I’m very new here, but not so new to canna and especially online advice and opinions.
Yup, 100% agree.
Brother is the real deal.
Right on!
I think CEC is kinda like the redheaded stepchild in a lot of horticulture, and not discussed enough.
It’s also a key issue (although not always) to localized dry spots and how they effect the entire plant.
Freaking electrons! 
Agreed with the rest cal and mag starved.
Went through this on the run I’m doing now.
Think mine was more on the magnesium side of thing so I treated with epson salt.
Then started cal and mag. Once a week..
Thanks man!. This is my 4th season start, and it’s my best batch of seedlings by far. Growth for most of the varieties has been strong. I got a good light meter and dialed in the Vivosun Led with the “seedling” setting. Par at about 100-150 for the babies, now since they are bigger, I upped light to about 250 Par. The leaf edges always looked to me like a nute problem. I’ve been watering them for about a week with a 1/2 dose of Terp Tea grow everytime I water, and now they are in about 1/2 gallon bags with pure Happy Frog, so I don’t think I will see continued problems.
I’ll put that “in my book” if I ever start in Coco Loco again. I like the way that Coco reacts to water compared to peat, but I didn’t know about the extra cal/mag need
You can use yucca extract for that. The saponins break the hydrophobic bond of peat, essentially making water wetter. Helps avoid tunneling and get even watering without dry spot.
