Just received my ebay Brinsea Octagon 20 Advance EX (w/humidity pump). Have it all set up and running and waiting for eggs due later this week. Is there any issue with mold building up inside this incubator and/or the humidity pump or tubing? I'm on well water - I didn't have anything growing in my hovabator after a 28 day guinea hatch, but then again my trays may have dried out once or twice. Is there something I should add to the water to keep any nasties out that won't hurt the eggs or the silicone tubing this thing uses? (Btw, it's great! popped right up to correct temp and humidity!).