Congratulations ! You have twins !
You have an interesting situation here @Blasting… And since they have separate stems, you’ll need to improvise yourself as a surgeon , lol
You will need to separate them. And sooner is better. Since they are “regular” seeds, the chance to have a male is greater. By doing so, you’ll risk losing them both. It’s a risk that you alone can decide to take.
You also can decide to let them grow together, one may take over the other or both can survive. If that’s the case, they may end up fighting for nutrients and have a slower grow rate or ending help each other… Who knows…
For the discoloration on the twins that look like burn it’s propably the paper towel you used for germination. It can contain chlorine, so the tap water if you did not filter it. They will eventualy pass through it, but probably will be stunt and grow slower.
You are most probably wrong with the rot problem. It’s most probably roots développement or mycorhizes, beneficial mushroom that work in symbiosis with the roots system for nutrients uptake and boost the immunity system.
For the one that have lost cotylédons with the shell , it’s done, no hope for this one, , i am sorry for your lost.
And like @bob31 mention, you’ll need to give them some fresh air at least twice a day. And be gentle on the water, only water spray around the base of the plantule when needed, for now, it look pretty wet so, it’s better if you let the soil dry a little
And Fafard as to be consider as a soil since it contain around 30% of humus. And contain very few nutrients in it, By memory I think it’s 0,45%, 0,03%, 0,08% of NPK, just enough until the cotylédons fall and then, you’ll need to feed them, the chart I have put for you previously on this topic is for soil. @Ray4x
And, all nutrients can cause nutrients burn, all of them, organics nutrients included. The only thing with that kind of nutrients is they have to be broken before they are available for the plant to uptake them, and that’s why mycorhizes and microbes are essential, they do the job. When you’ll have to transplant, you’ll need some. Big surfaces , gardening store and hydro shop have it.
Have a nice time “blowing” stuff up North my friend, see ya when you come back