I think the five ice cubes was bad advice. It seems like the ice cubes would sit there and keep the soil moist for a pretty long time.
Here's a bonsai tips thread with information about how to water. viewtopic.php?f=36&t=1479
The mold/fungus is a sign the soil is staying too wet, too much of the time.
Incidentally your bonsai is a ginseng ficus tree. You didn't show the top of it. Does it have any leaves?