Withering lower leaves on 4-6 wk. seedlings

[Greatgardens]

Originally Posted by zipcode

I really don't think that's a lack of nutrition problem.
Could be a toxicity of some kind, maybe due to water? But hard to say.

The water is an interesting thought. I've used the same watering container for years and years. AFAIK, it has never been cleaned out. I do see some "pink stuff" on the walls as well as a lot of lime scale, so time to clean it out. One less variable. As I write this, it is being de-scaled. I'll neutralize it when finished. It may take overnight to finish.