Just about everyone who lives in Arizona has "Hard Water" at home. That means your water contains dissolved minerals such as calcium and magnesium. How "Hard" your water is depends on how many grains of the minerals it contains per gallon. Water that contains more than 1 grain per gallon is considered hard; water with more than 10.5 gpg is very hard. A typical glass of Arizona water has at least 15 gpg. You probably can't taste it, but, you can definately see it.  Hard water can cause two noticeable things to happen: the chemicals can cause a chalky film called limescale to form on the inside edges of your faucets and drains. You might see the same thing inside your teakettle.  Its almost certainly inside your water heater. Those chemicals can react with soap to prevent it from lathering. It can give the soap a scummy feel and make it difficult to wash off. The solution: Install a water softener. That device, which can cost $400 to $5,000 - depending on how big your home is and whether you want it installed by a professional - will replace calcium and magnesium ions in your water with sodium ions, which do not react badly with soap or cause limescale to buildup on pipes.

Is it worth the money?  It will pay for itself with what you save on plumbing repairs, new appliances and laundry soap. Here's what you will save if you install a water softener, according to a spokesman for Water Treatment Technologies in Phoenix: your clothes will last longer - up to one-third longer - if you wash them in soft water than if your washing machine runs on hard water. You'll spend 80 percent less on soap and cleaning products if you clean with soft water, because hard water prevents soap from lathering, so you need to use more.  Energy bills are lower in homes that have soft water. Studies show that even an eighth of an inch buildup of limescale in your water heater can increase energy bills by 20 percent. (Tip!) Don't base your decision to buy a water softener on price alone. The company you buy from is just as important as the equipmnet you buy. Deal with a company that rents water softeners as well as sells them, so you have a choice. Look for a dealer who services all brands of equipment, not just one.  Choose a dealer that can deliver salt (for the softener) to your home if you're unable to pick the salt up.

Now, what about the taste of your water? That's a different problem with a different solution. The water supplied by Arizona's cities is clean, safe and useable.  In order for it to taste as good as it can, there is something more you can do. A  will give you bottled-water quality with the convenience of your kitchen tap. Installed under the sink, a reverse-osmosis system is perhaps the most effective form of water filtration. The system removes up to 98 percent of metals, pathogens, chlorine and dirt, so your water smells and tastes like nothing but water. A reverse-osmosis system is different from a water softener, which removes the minerals that make your water hard - all over the house. A reverse-osmosis system works just on your kitchen faucet because it's for drinking water only.

You'll pay between $160 and $1,800 for a reverse-osmosis system - depending on the size of your house and the quality of the system and whether you're going to hire a pro to install it.  Many Arizona households have a water softener and a reverse-osmosis system; both are worthwhile investments!

For most families installing tankless water heater yields a substantial savings on utility bills, and some gas/propane models qualify for a $300 energy tax credit. No standard tank-type models qualify for the credit.

Tankless water heaters are not new. They have not been popular in American homes, but are common almost everywhere else in the world. It is a proven technology, and you never will have a rusted-out tank to replace.

Tankless water heaters are small and are usually hung on the wall or recessed (gas models) in a wall outdoors. Much of the cost of heating water with a standard tank-type water heater results from heat being lost through the walls and top of the tank. During summer, this heat loss to your home makes your air-conditioner run longer, so it is a double cost. During the winter, it does heat the air, but the water heater usually is in a utility room or basement, where warmth isn’t needed.

A tankless water heater has high output burners (gas) or heating elements (electric) to heat the water only as it is needed. If you do not use hot water overnight, the unit does not come on. In contrast, a tank-type model may come on several times to replace heat lost from the tank.

In addition to the utility-bill savings, a tankless water heater can supply enough hot water for endless showers, whereas a tank type water heater can run out of water by the third long shower. If you have just washed the dishes or done the laundry, the hot water may run out by the second.

The drawback to a tankless water heater is the instantaneous hot-water output is limited by the heating capacity of the unit. Depending upon the heating capacity, you may not be able to take two showers while running the clothes washer. This is a minor inconvenience to stagger the high-hot-water-usage tasks.

Gas models have the greatest instantaneous hot-water output, up to six gallons per minute. Because you seldom use straight hot tap water, this is more than adequate.

If you’re replacing an electric water heater, you’ll need additional circuits and wiring to a tankless unit.

No matter which type you need, select one with modulating heat output for steadier hot-water temperatures.