Hmm, if they start like that I would check that coco with a slurry test or have a look at the drain water EC. Some coco will act really weird out of the bag/brick, you can throw 1.7 EC in and it may come out 0.5 EC I'm sure youve seen it Some say it's ok but I don't trust that shit. Maybe it's the unbuffered exchange sites stripping all the cations from the solution or something. When I start my coco pots I always run a decent amount of nutrient water thru there to 'make sure' ... I like it if the output EC is at least close to the input. I have had unexplainable problems with clones while doing everything right due to this.
Well, I donno if you are reusing a batch or a fresh mix. Even if they could have used a little more light they shouldn't look so messed up I think. The Coco A&B formulas I have tried all have enough of those elements for my tap water (60 ppm Ca)
Think I agree with kandi also, looking at the perlite now, maybe it's just a bit too wet in there. this kind of problems also looks like something I seen on overwatered soils for seedlings, like some organic mix which also has clay in it...I think with EC 1.2 you don't need ot worry super much about salt build up using a wet/dry cycle with adequate amount of drain water until week 3 or 4
edit: lol, actually maybe it's just the color from root stimulator?
Yes, I’m starting to think about it could be the medium 70/30 as the 60/40 or plain coco I never have problems with and I’ve asked another person who’s a master coco grower I know and he’s said the same thing. Should have none better and stuck with what I normally do never had a problem at this location.
So the plan is to get these seedlings out of that mix into some decent plain coco and flush them then start again sort of thing, I’m thinking of getting some other seeds on the go just in case anything comes up as I’m a bit on a time schedule with this one, so rather wait a week on top of that I will germinate some more seeds just for a back up, I don’t really want todo this as I know I will pull these around but it’s there just in case, can’t waste another week on this location.