Hello, I live in Montana and I got some cabin fever during the long winter and decided to get a head start on growing a garden. So I bought some dirt and a couple containers and planted some seeds. I ordered some pawpaw seeds and decided to plant them. The instructions said that the soil needed to be 10 inches deep, but once I dumped out the dirt I realized I didn't have that much. So I piled it all up in one corner with a little bit at the bottom and planted the seeds. Then to take up the extra room at the bottom, I put a little fountain and an empty date box and filled it with water and put 2 fish in there. I looked up on the internet that fish need large tanks to live in because they need fresh water and air, but, being pretty stubborn, I decided that instead I should just keep dumping more water in there. The remaining goldfish seem to be doing fine (Although I started with 4) but the water's yellow and mucky. I've had this little thing going for about a month. I put it over the heater because it said the seeds need heat. Only the half of it that the seeds are in is over the heater, the other half is on the desk. I read that it needs drainage, so I tried putting some holes in the bottom of the plastic container but instead it put a big crack in it and now it's on top of the lid. The seeds aren't supposed to germinate for a couple weeks, but there's something white spreading on the top of the hill of dirt. At first I thought nothing of it, I guess I just automatically dismissed it as something I didn't understand but didn't matter, but today I looked at it and realized that it's spreading over the whole dang thing and for once I really thought "What the heck is that??" So I tried looking it up on the internet. My mom is worried about it and says that mold is very serious and can cause very bad problems and thinks I should throw it out. But I remember starting plants indoors almost always has mold growing on it. But I'll try to explain what this thing is=it's white, almost looks like lichen or moss, but not really fuzzy, it's kind of indescribable. It's weird. It looks like the dirt just turned white on top. What I don't understand is that everywhere I read about mold it says it's from overwatering, but it's not growing on the wet part. I don't water the hill much, but the bottom gets a lot of water, because I keep pouring in more water for the fish. It overflowers, but it doesn't reach the part that this stuff is growing on. It's almost dry, actually, so I don't understand how this can be mold. It's not growing where it's wet, it's growing on the dry part. So my question is, what is it, how common is it, do I really have to take care of it, and is it a problem?

I to had this same issue a few years ago I think what you have is a fungus rather than a mold issue. what I did to remedy the problem was scrape the white fungus off the soil surface and then applied a plant fungicide to the soil surface wetting the soil well(careful of the over spray around the fish) (use cardboard as a shield) hope this helps Tim