My tomato seedlings look like they are having damping off symptoms even though I've used living soil like it's suggested in Dirtdoctor's vegie book. It suggests "placing colloidal phosphate on the surface of planting media". What and where do I look for in the stores? Then, there is an addition saying that "treatment with cornmeal is also effective". Has anyone here had any experience with these items? Any other suggestions that I could use? In the meantime, I'm going to sprinkle cornmeal on top and see what happens. I've not had much success in the past with seedlings, and I really desire to learn how to do it well. Many thanks for help.

Unfortunately there is only one thing to do:

Start over, you don't want to grow plants that the seedlings weren't perfect from day 1. And boil or solarize your seed mix before you start again in different containers. Living soil=dead seedlings. This might ruffle some feathers here but I can't see how it isn't "natural".

There is plenty of time to get maters ready for March at this point.