You say you had seedlings producing leaves in water...were they bareroot at that point? And you then potted them in rich saturated loam...are the potted plants then immersed in water? That leaf damage looks very much as though the leaves have dried. And that can come from root damage. When you potted them up, it is likely roots were damaged and unable to absorb sufficient water to maintain the leaves.
If your soil is has a sour smell, there is too much organic matter in it that is rotting and likely producing anaerobic conditions, which will lead to root rot.
Can you give more details on how the plants are now being kept...are the pots in water? And where did you get the soil?
Truth is not what you want it to be; it is what it is. And you must bend to its power or live a lie.”― Miyamoto Musashi
"Knowledge speaks, but wisdom listens." ~ Jimi Hendrix
“The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.”― Stephen Hawking
Craig