Ugh! Damping Off!

[Labradors2]

I've never had this problem before, but this season it must be my turn.

I germinate in damp paper towel, and that went well. As I potted them up, I put my plants on a sunny windowsill until I had enough to go under the grow lights. I turned them on at night in my cold basement. There are tomatoes, peppers and eggplant. I've lost five out of 17 of my first tomato seedlings (which were just getting their second leaves) and two peppers, but more are failing.

Two things were different this year. I used Pro-mix "for herbs and vegetables" which I love for my large pots of container tomatoes, but which I've never used for seed-starting before. I don't see why that would be a problem.

I found a fiberglass "nest" in my bag of potting mix, indicating that a mouse had been in there over the winter. There was no other sign of anything, and the fiberglass looked clean. I decided that any possible mouse excrement might be a useful addition to the mix, but now I wonder????

Could it have been the mousy mix that felled some of my seedlings?

Linda