I've been growing some apples from seed. I had four growing in one pot, then transplanted them into four separate pots. They have survived the transplant I believe, but one of the pots has a light-blue mold growing on the surface of the soil.
I'm not exactly sure what kind it is or where it came from, but the other three pots haven't shown signs of mold growth yet, and hopefully I'll never see any.
Each of the pots have the same schedule of watering and sun light (in response to a previous answer, likely over watered), they have the same soil found here. (It's a mixture of mostly that and some potting soil, but the potting soil hasn't been the cause in the past.
They're in small pots, and I'm living in a really small space so making a 5-gallon bucket of bleach-water isn't optimal. How can kill the mold in the pot, and prevent it from growing in the other three?