Mr. Raw, I am wondering if your mung beans have maybe been irradiated or treated somehow. If your tap water is safe to drink I can't imagine why the beans would be rotting. Have you tried various sources of mung beans to see if the all perform the same? Any way you can warm an area for them if it is cooler temps keeping them from sprouting? Like a mat for reptiles, using the heat of the top of your fridge?A small box or modified cabinet (for air flow while blocking light) set in the sun?
I may have to go back and read as well but I think you said they are often below normal sprouting temps. I hope you soon get it sorted out. Mung are about my favorite sprouts. I've taken a recent liking to lentils. I like them best when the radicle has just emerged though, and mung when they are a considerably longer. first time I tried lentil I let them grow long and did not like...woody and bitter.
