Wait, do you actually think rainwater is different from distilled water for carnivorous plants? I've been growing these things for 6 years now and I have to disagree a bit. Rainwater from a bucket can pick up all sorts of dust and pollen and even bacteria from your roof or whatever it's sitting in. I lost a bunch of flytraps one summer because I got lazy and left my bucket out too long without cleaning it. Now I just buy distilled from the grocery store for $1 a gallon and call it a day. Once the minerals are gone, the source doesn't matter much.