Stationed next to our newsroom scanners, I hear fire calls all day long. Fortunately most are doused by our local firefighting heroes preventing the worst, but even a relatively small fire can wreck what should be a time for fond memories.
Never let the water level recede below the cut end of the tree. If a stand becomes dry, the tree should be removed immediately. Don't use any additives in the tree water.
Water usage: Christmas trees will use 1 quart of water per 1 inch of cut end diameter per day. So a tree up to 6 1/2 feet takes 1/2 gallon of water a day; up to 10 feet, 1 gallon; over 10 feet, 3 gallons.