Dingy, scratchy clothes. Dull hair. Spotted dishes and shower doors. Crusty shower heads. Sound familiar? Probably - a good majority of Americans deal with inconveniences like these every day. The likely and often unsuspected cause? Hard water.
One of the most common water-quality issues, "hard water" is simply water with a lot of minerals in it - namely calcium and magnesium. While these are naturally-occurring, excess amounts in water supplies can cause all sorts of problems, ranging from minor annoyances to potentially serious plumbing issues. And of course the more serious things are often hidden from sight.
The hardness of water is commonly measured in grains per gallon: 3.5 gpg is on the lower threshold of hardness, and anything over 10.5 gpg is considered extremely hard. The presence of limescale is the most obvious sign that your home's water is hard, but it isn't the only one. We mentioned the clothes and hair, but dry skin, poor soap lathering/ineffective cleaning, and low water pressure are also indicators. Those on municipal water supplies should be able to obtain a free report on their water quality from their provider, and testing kits are widely available for everyone else.
Did you know? The calcium, magnesium, and other minerals that make water hard aren't health risks; many studies have even shown a possible correlation between the long-term ingestion of certain minerals and a reduced risk of cardiovascular disease! Thankfully, there are plenty of other ways to get your minerals that don't entail potential plumbing problems.
Among the casualties of hard water, the water heater might be the most vulnerable. Despite manufacturer maintenance guidelines and our own appeals, water heaters tend to be ignored until they can't be, providing ample time for the buildup of scale and sediment in the bottom of the tank. This wastes energy (the sediment heats up before the water can) and can shorten the life of the unit. And it's not only old-fashioned tank heaters that are at risk: scale can build up in the heat exchanger of tankless water heaters, making heating inefficient. This can lead to overheating and even burnout. Dishwashers and washing machines are similarly at-risk.
Pretty much any plumbing fixture is negatively affected to some degree by hard water: ruined finishes, damaged washers and seals, and valve blockages are typical.
With pipes - particularly steel ones - the concern is blockages. Most of the time they're only partial, and cause an annoying but generally harmless drop in water flow. But given enough time - and hard enough water - it is possible for a pipe to become clogged enough to increase stress on the pipe (which could lead to leaks), or even completely blocked. Thankfully, most homes built or repiped after the 60s will have copper or plastic pipes that hold a much lesser risk of significant mineral build up.
It all sounds pretty scary, but many people either don't notice the hardness of their water, or don't really care. Sure, a lot of the resulting issues are annoying, but most people are lucky enough to avoid clogged pipes and failed water heaters. For the unlucky that are forced to deal with the full wrath of hard water, ion-exchange water softeners are generally recognized as the best solution (reverse osmosis filters will also do the trick, but waste more water and cost more to operate, especially with very hard water).
Please note: Water softeners are not permitted in some areas. Be sure to check with local authorities before considering one!
How do water softeners work?
It's pretty simple: a negatively-charged resin is housed in a tank, and saturated with positively charged sodium ions. Hard water - full of calcium and magnesium ions with even stronger positive charges - goes through the tank. Because the hardness ions have a stronger charge, they can knock sodium ions off the resin and form their own bond to it. This is "ion exchange".
Most of the hardness minerals are removed from the water, replaced by a relatively small amount of relatively harmless sodium (but those on sodium-restricted diets should consult their doctor before switching to salt-softened water). Eventually, the hardness ions saturate the resin completely, and must be removed in order to soften any more water. This is the point of the "regeneration cycle". A second tank, full of brine, is run through the resin. Although the sodium's charge is weaker, the sheer amount of it in the brine is enough to replace the hardness ions, which are flushed out of the unit and into a drain.
Those sensitive to sodium or concerned about brine discharge can use potassium chloride in place of sodium chloride in a water softener - it works just as well, but is a bit more expensive. Also, beware claims made by manufacturers of magnetic or electronic "softening" devices. Since no ion exchange takes place, there is no removal of the minerals that cause problems from your water, and there is little to no scientific evidence that any electronic or magnetic devices will prevent scale buildup in your plumbing system.
Deciding whether to use a water softener is a tough call. Clearly, those sensitive to the effects of hard water on hair and skin won't have much to think about, and neither will those flushing and resetting their tankless water heaters all the time. But what if your biggest problem is embarrassing glassware? Is it really worth it? That's one question we can't help you with. But keep in mind that minor annoyance could be pointing to something hidden and much more serious.
Our advice? Find out just how hard your water is, and if you're using a traditional tank-style water heater, flush it out. This will give you some idea of the severity of the problem - if it's a newer heater (or was recently flushed) and still has a good amount of sediment inside, it's safe to say you've got some fairly hard water that could be causing more hidden problems elsewhere. With more frequent maintenance and increased awareness, it is possible to avoid most problems, but softening provides the only guarantee.