Anissa,

I use a small painting knife as a tool to "cultivate" the green stuff under. And I do aim a small fan directly at the plants. The plants like the "exercise" and the improved air circulation dries the surface of the growing medium.

MM

I sometimes get this, and I think it is from overwatering in cold temperatures especially. Like this year I had my seeds starting next to an unused door, where it gets really cold. So I had algae. It didn't seem to hurt them, though.

Try to water from the bottom, in the tray, and pour the water off before the soil surface gets wet. Also, a layer of finely milled sphagnum moss on top of soil will inhibit algae and fungus growth.

Thank you for your responses. I really appreciate it.

Anissa

A little peroxide on a q-tip could wipe off mold etc.
(I have done this with no damage to seedlings)

This was a common experience in a greenhouse I worked in and it is from over watering and humidity. My boss was famous for over watering and if left it will hurt the plants because it will take all the water and won't get to the roots. we also found that the base of the small plants that the green touches eventually becomes damaged. I would take a popsicle stick wipe off and add fresh soil to the top and allow to dry the remaining soil.

I just googled this question and came up with your responses which I really appreciate. I'm off to my green house to direct my fan at my plants at least so they get a bit of wind. I'll stop worrying about the green stuff and water less. Thank you.

i just stumbled across this from google. Very interesting, but mine are at the bottom of my pots of growing plants. They're about 2 months old now or more, I don't really know. Just thought I'd try growing some veges on my bit of balcony space from some seeds I kept... But it seems i don't have to worry too much about it??

I just discovered this problem today after my LED lights turned off and I turned the white light on. I am going to try just wiping it off the surface. I noticed that it's only on my older seedlings that I need to repot. I am adding better ventilation to my little greenhouse, so hopefully this will help. Thanks for the suggestions.