I've been growing AF's for years and I've never had a problem with diseases. I did learn early on when watering the plants, do not overwater; this will cause "root rot" and once this starts, there is usually no way to stop it. You have to dispose of the plant. Some people may already know this piece of advice--always water AF's from the bottom and never at the top, give it just enough water for the plant to be able to soak the water up in a couple of minutes. If it takes longer than 2 minutes, you've given it too much water. Let the plant dry almost completely out before watering again. AF's like "semi-moist" soil.