"If it's yellow, let it mellow. If it's brown, flush it down." If you've ever gone to summer camp or lived in a drought-prone area, you've heard this well-meaning advice. Is it really a good idea to let urine mellow, though? Read below to find several reasons why foregoing the flush isn't as beneficial as you might think (and some friendly advice should you choose to let it mellow, anyway).
In most cases, if you're drinking enough water to stay hydrated, your urine will not have a strong odor—especially if you flush it right away. Certain foods, however, can make urine pungent. No matter what, if you allow urine to set for several hours (particularly in warmer climates), your bathroom is likely to develop an unpleasant smell. It's not a health risk, so if you really want to let it mellow if it's yellow, there's no need to worry about germs. Urine is sterile, even if it is stinky. To minimize the smell, you'll want to flush after every two or three pees and scrub the toilet at least once a week, if not daily.
Sitting urine stains your toilet.
If you don't clean your toilet frequently, letting it mellow is not for you. Stains can develop if the urine is left sitting in the bowl overnight or for extended periods. Combined with hard water, mineral deposits from urine can have a nasty effect on your toilet bowl's appearance.
Should you find yourself with a tough stain, flush the toilet and add a cup of distilled white vinegar to the bowl. Allow the vinegar to sit for 20-30 minutes, and scrub the toilet with a brush. Flush and repeat until the stains are gone. Avoid using pumice and other abrasives, as they can scratch the porcelain.
Postponing the flush doesn't save much water.
Saving water is a good thing, but you may not be saving as much water as you think by flushing less. Modern toilets only use 1.6 gallons of water on average, compared to older toilets that use 3 gallons or more. The average person urinates 6 times per day. Over the course of a year, that means most people will use 3,504 gallons to flush urine. If you want, a plumber such as http://www.a1plumbers.com can instlal more water efficent toilets.
While that sounds like a lot, a 10-minute shower will use up to 70 gallons of water. By cutting your shower time in half, you can save as much as 35 gallons of water, which is more than three times the amount you'll save by reducing your flushes. You can also save more water by only doing laundry or dishes when you have full loads.
It doesn't save much money.
The average cost of using a gallon of water in your home is two-tenths of a cent per gallon, or $2 per 1,000 gallons. Consider the above numbers that the average person uses 3,504 gallons of water for urine-related flushing. When you do the math, the total cost of flushing after urinating is only about $7 per person per year. If you're only looking at leaving urine in the toilet from a frugal perspective, $7 isn't much of a savings.
For all that can be said against leaving urine sitting in your toilet bowl, it does save water. So if you're particularly eco-conscious, every bit helps. In areas where droughts are common, limiting toilet flushes can help significantly when it's a community effort. If you have a small well with little water or a septic tank that's nearly full, it's also helpful. All in all, flushing urine or leaving it won't make a big difference either way in your wallet or your water usage, but it will make a difference in the smell and appearance of your bathroom.