Did you add any hydrogen peroxide to the water? That's what I do...just a few drops to a couple ounces of water.

Also, make sure that you change the water (especially if you haven't been using hydrogen peroxide) weekly. I would remove the moldy seeds and throw then away. From time to time we all get moldy seeds, ( at least I do), sometimes I wonder if it isn't the water. Good luck....Donna

I've added hydrogen peroxide to the water and there have been no more mold spots showing up. I have roots on most of the seeds, I'm just waiting for the shoots so I can transfer the seeds to soil.