Q Are no-salt water softeners effective? Is there real science behind their operation?

A A water softener is a water treatment system that uses salt to remove minerals responsible for creating hard water, such as calcium and magnesium, and replaces them with soft minerals, such as sodium and potassium.

The no-salt system you're referring to is not a water softener and does not remove those minerals. Instead, salt-free units often called "water conditioners" or "descalers" can help reduce the buildup of lime scale (that hard, chalky white substance that you see in dried water spots) and other chemicals.

Water conditioners, which typically fit around a pipe, are said to change the chemical structure of minerals in water as it travels through the pipe, by using magnets, electrical current and crystallization polymers. The descalers prevent those solids from being deposited inside pipes and on fixtures.

They're not entirely effective, because places where water sits -- in your water heater, for example -- will still get a buildup of scale. However, no-salt systems don't add chemicals to the water and there also is no waste water, as there is with water softeners.

Some no-salt systems work better than others, of course. Some are effective at preventing scale, but they will not "soften" the water, allow you to use significantly less soap or make your clothes whiter and brighter, as many claim.

Here are some reasons you might want to opt for a water softener instead of a water conditioner:

•Hard water can reduce the lifespan of appliances such as dishwashers, ice makers and washing machines and add additional wear to your clothes.

• Soft water is easier on your plumbing, your fixtures and your skin.

• A water softener is energy-efficient, because hard water can increase the electricity consumption in your home by coating water heating elements.

•There are more options on the market now for water softener systems that require less salt consumption.

If you're concerned about sodium in your drinking water, you can add a reverse osmosis system, which will make your softened water sodium-free.

Before you buy a water conditioner or a water softener, do your due diligence and investigate the product and company supplying it. Be sure to deal with a reputable company that offers a money-back guarantee.

ANGIE HICKS, ANGIE'S LIST

Dealing with discolored grout

Q I used a bad floor sealer when I redid my shower. I'm afraid I'm going to have to redo all the tile in the shower. The grout has been contaminated with a dark sealer and there is no way to get the discoloration out of the grout. What can I do?

A You have three ways to approach this problem.

Plan A: Try cleaning the grout. Go to a professional tile distributor with a photo of your shower floor and ask about tile cleaners. Maybe you'll get lucky and they'll sell you a professional cleaning solution.

Plan B: You may be able to chip out or grind out all the discolored grout from between the tiles. Once you carefully remove and clean out the grout, you may be able to regrout the shower floor. Just be careful not to crack the tiles, or disturb the shower pan membrane.

Plan C: If nothing else worked, this may be your only choice left. Hire a professional to break out the tile floor, grout and concrete "mud" base from the shower pan.

Once the pan and drain are determined to be in good shape, a new shower floor can usually be installed without disturbing the walls.

While the first two options are relatively inexpensive, the last option can be a bit pricey. If you go with Plan C, request price quotes first before you seal any deal.

ED THE PLUMBER, HGTVPRO.COM