a little green stuff in the germ trays

can't take a photo til i get home, but the surface of the mix i sowed seeds in is starting to develop some green algae/mold/whatever. i do keep the tray under a dome and on a heat pad. what should i do about this?

The green stuff is usually harmless, are you measuring the temperature?

I haven't been. Just trays on pads under domes. First try germ'd 47/50, second tray was around 60/72. Nothing different but never had the green funk before!

Algae is ubiquitous; you can control but not eliminate it.

I bottom water. Originally I'd let the trays sit in water until they had their fill, but this would leave the soil very wet, even up top, and as a result I had algae growth.

They need a wet environment to grow as well as light. If you're bottom watering keep an eye on the cells and stop when you see water nearing the top so it stay wet for days. You could put a layer of something else at the top that doesn't hold water as well, maybe stone or sand.

The humidity dome is definitely going to help the algae, but if it's necessary for your peppers it's going to have to remain a double edged sword. I'd recommend a fan later on to keep the air moving.

I've had some success mixing baking soda in water and spraying the algae. It's supposed to be to basic for it to grow. Try not to get it on the plants (though it won't hurt them much). If you have enough room just sprinkle a tiny bit on there or make a slurry with more baking soda, less water and apply it carefully with a q tip

You could try spraying some 3% peroxide.