Eliminate the drawbacks of hard water in your motorhome.
By Mark Quasius, F333630
Motorhome owners often face challenges that people in sticks-and-bricks homes don’t encounter. One example is water quality, which, as travelers find, varies widely by location. Recent articles in Family Motor Coaching have noted that water filtration and fresh-water sanitizing are the keys to a safe drinking supply. However, filtration does not address water hardness, which requires a different approach.
Hard water contains relatively high amounts of dissolved minerals, mainly calcium and magnesium. Hardness is measured in terms of grains of such minerals per gallon. (For comparison, a typical aspirin contains about 5 grains of material.) Water that tests at 1 grain per gallon (gpg) or less is considered soft; 1 to 3.5 gpg is slightly hard; 3.5 to 7 gpg is moderately hard; 7 to 10.5 gpg is hard; water above 10.5 gpg is very hard. To determine your water’s hardness, the Water Quality Association suggests buying a home-based testing product or contacting a state laboratory or local water treatment professional.
Hard water is actually safe to drink. The World Health Organization says hard water can be a good dietary supplement for needed minerals. But there are downsides. Minerals such as calcium carbonate cause a lime scale buildup, which can affect your fresh-water plumbing system in a number of ways. The lime scale can clog water lines and cause corrosion when two dissimilar metals come in contact. Hard water also inhibits soap suds, leaves a soap scum in the shower or bath, and deposits white calcium residue on glassware and dishes after dishwashing.
We have always had a good filtration system in our coach, but we have never addressed hard water. While attending an FMCA convention, we stopped at the booth of RV Water Treatment (www.rv-water-treatment.com) and talked with Mark Shumaker. He was very knowledgeable, having worked in the municipal water treatment industry for 30 years. He is also a motorhome owner. He brought us up to speed on how to deal with hard water, and we wound up equipping our motorhome with some of his products.
First, it’s important to understand that filtration systems don’t remove the minerals associated with hard water. Rather, they remove certain contaminants from the water. Basic sand filters remove sand and large particles. Activated carbon filters remove chlorine, volatile organic compounds, and hydrogen sulfide. A bacteriostatic carbon filter will prevent bacteria from growing in the filter. But the hard-water minerals remain.
Reverse osmosis systems can remove the minerals that cause hard water, but they have drawbacks. Only a fraction of the water entering the system becomes usable; the rest is waste, which can be an issue for an RV. Typically in an RV, a reverse osmosis system that delivers 5 gallons of treated water a day also produces between 20 gallons and 90 gallons of waste, mainly because of the low pressure (40 psi) common in RV water systems. Reverse osmosis systems use osmotic pressure to force water through a semipermeable membrane, which separates clean output water from the source water on the incoming side of the membrane. This process filters water down to the molecular level, so while it is “clean,” the minerals that are important for health also are removed. The World Health Organization has said that drinking such water over the long term could lead to cardiovascular disorders, muscle cramps, and fatigue.
How Softeners Work
If you want to avoid the pitfalls of a reverse osmosis system, and remove hardness from water that filtration systems can’t, you need a water softener. Rather than using a filter, the softener works via an exchange of ions, which are electrically charged particles. The softener is filled with a polymer resin in the form of small beads. A salt bath coats the beads with sodium ions. As water passes through the beads in the softener, calcium and magnesium ions are exchanged for sodium ions, effectively neutralizing the hardness.
A water softener’s sodium ions eventually become depleted, and the beads are saturated with calcium and magnesium ions. When that happens, the softener cannot treat any more hard water and requires regeneration. In that process, brine passes through the softener, and the ion-exchange operation is reversed. The salt picks up the hard-water deposits from the resin beads and carries the deposits into the waste water. Once the resin has been cleared of the calcium and magnesium deposits, the brine continues to coat resin with sodium ions so that it can continue to soften incoming water. Residential softeners are equipped with metering systems and automatic regeneration controls to do this automatically, based on the volume of water. But portable units don’t have that ability and require manual regeneration. Inexpensive test strips allow a motorhome owner to measure hardness according to a color chart to determine when regeneration is necessary.
When selecting a softener, keep in mind that misleading advertising might claim that a water softener can treat a certain number of gallons. In fact, water softeners treat a given amount of hardness before regeneration becomes necessary. The same softener can treat many more gallons of mildly hard water than extremely hard water. In our coach, we typically have been able to travel for two to three months without requiring regeneration. But in one case, while staying in Texas Hill Country where the water was extremely hard, we could go only three to five days before regeneration. Generally, areas such as the Pacific Northwest and New England have the softest water, while the Great Lakes states have moderately hard water. Arizona, New Mexico, Texas, and the southern portion of California are known for extremely hard water.
The larger the size of the water softener, the longer the period between regeneration cycles. For a motorhome owner, it becomes a trade-off between the convenience of a small, compact, easy-to-store unit versus a larger unit that has a longer running time between regeneration cycles. Another consideration is whether to permanently install the softener in the motorhome or to keep it portable, placed next to a campground spigot. Softeners travel best in the vertical position so as to prevent damage to the strainer basket. Carrying a larger unit horizontally may not be best for its longevity.
Water softeners need to be sanitized occasionally, just like the rest of your fresh-water system. Chlorine is not ideal; I don’t recommend it. Household bleach is typically only 6.5 percent chlorine, and that level drops drastically through gasification — as much as 50 percent in a month — so shelf life is short. Chlorine also penetrates into plastic and can harm fresh-water tanks, Pex water lines, and water pump seals. Lastly, when chlorine comes into contact with organic material, it produces trihalomethanes, which are known carcinogens.
Sani-System is an EPA-approved product for sanitizing water softeners. It is a quaternary-ammonium-chloride-based disinfectant proven to kill 99.9 percent of bacteria in 60 seconds. It must remain in your fresh-water system for only a few minutes. It doesn’t attack the plastic lines and tank walls, so it flushes out without the residual traces left by chlorine. It’s even safe to use in reverse osmosis systems without damaging the semipermeable membrane. Sani-System is available in easy-to-use packets filled with a liquid concentrate that can be poured into a filter housing or into water hoses.
We frequently encounter hard water when we travel, and at home our water has high levels of iron. Water softeners are great for removing calcium and magnesium from hard water, but they aren’t very effective on iron or sulfur. (The latter can cause an offensive odor.) So we decided on a two-step approach, and RV Water Treatment had the perfect system for our motorhome. The first step was to choose a system that oxidizes and filters iron, manganese, and sulfur. Then we chose from among RV Water Treatment’s three types of softeners.
The top-of-the-line model is a solar-powered, automatic regeneration softener with a brine tank, for $895. It is perfect for a permanent site, but too large for us because we are mobile.
A semiautomatic softener system, which includes a brine tank and a mechanical timer, is available for $549. This model eliminates the need to place salt in a prefilter housing, but the brine tank does take up additional space. Because I decided to mount the softener and iron filter in our motorhome, I felt the semiautomatic model would not be best for our situation.
We chose the basic system, which costs $339 and consists of a softener fitted with a prefilter. The unit has a 0.5-cubic-foot resin tank and is capable of removing 15,000 grains of hardness, which means it can soften about 750 gallons of water at 20 grains of hardness. (Many competing models treat only 8,000 grains.) It can operate for as little as three weeks or as long as two to three months between regenerations, depending on the amount of water being used and water hardness. Inside the head is a distributor basket that effectively distributes water through the resin beads. The prefilter helps extend the softener’s life by keeping particulates out of the resin tank; it also serves as the resin bin during regeneration.
When the softener needs regeneration, I simply close the shutoff valve and remove the prefilter housing. I generally throw away the inexpensive 20-micron melt blown polypropylene prefilter element, then fill the filter housing about two-thirds full of solar salt and install the distributor tube. I then open the valve, go inside, turn on a sink faucet, and let a stream of water the diameter of a pencil run for 45 minutes or so. After the saltiness is gone from the water, I remove the distributor tube, pop in a new $3 prefilter element, and we are good to go again.
As for installation, many motorhome owners choose to simply set the softener on the ground and run a water hose through it. Or, you can mount the system inside, like I did. At minimum, you would run some Pex tubing to the softener and then back to the utility bay to feed the coach. That might take a couple of hours, depending on the location of the bay and softener. In my case, I bypassed the water softener with a single line to feed the icemaker on the refrigerator and to provide unsoftened drinking water at the dispenser. This line has a bacteriostatic filter to provide clean water and minimize any taste issues. The iron filter and water softener are connected with garden hose fittings, so they are easy to remove and bypass when winterizing the motorhome.
Some people may become concerned about how much sodium a water softener adds to drinking water. According to the Mayo Clinic, an 8-ounce glass of softened water typically contains less than 12.5 milligrams of sodium, which falls within the U.S. Food and Drug Administration’s definition of “very low sodium.” Still, the clinic says people concerned about the amount of sodium in softened water might want to consider a system that uses potassium chloride instead.
The end result: We now have great water quality regardless of where we are located. We no longer open the dishwasher only to find white lime deposits on our cups and water spots on our silverware or glassware. Showers are much better with no more soap scum, and everything rinses clean. In short, we are very pleased.
RV Water Treatment, 331 E. Railroad St., Bronson, MI 49028; (269) 221-4670; www.rv-water-treatment.com