The white is calcium and the green tint is copper. You can get your water tested to determine your exact minerals so you can counter the effects.

FEMA states that stored water should only be kept for 6 months before changing out unless it was commercially made as they use different ways to make shelf life longer.

Some stored water will get a sulfur smell in less than 2 months. This is from hydrogen sulfide/sulfates. Well water from either shallow or deep wells can contain the sulfur.(primarily found in shale and sandstone deposits--like most of Colorado) If you are using a municipal water supply there is chlorine added that will reduce this. Well water will need to be chlorinated before storage. 1 to 2 drops per gallon is sufficient. Don't forget that containers need to be food grade and sanitized as well.

Potential Side Effects from Sulfer/Sulfate:
Sulfate
Sulfate may have a laxative effect that can lead to dehydration and is of special concern for infants. With time, people and young livestock will become acclimated to the sulfate and the symptoms disappear. Sulfur-oxidizing bacteria pose no known human health risk. The Maximum contaminate level is 250 mg/L.