Well after reading over the thread it doesn't seem like you were over watering, which was my first thought so my next wild guess would be soil and /or Ph. What soil are you using? Is it pre-fertilized? Those pots have drainage, right??

I have started seedlings in soil that was too hot, too rich for young seedlings and its essentially the same as nute burn....stunted growth, yellowing leaves, etc. Even some organic soil is too rich for some strains. Now I just start in seedling soil or Fox Farms Light Warrior.

Not saying thats your issue, but it does have similarities to what I have experienced.

Good luck! :thumbsup: