Pools and "green" don't typically go together.
The words "green pool" bring to mind algae, a definite backyard-bliss buzzkill. And using the modern term "green" with pools also seems incongruous.
Pools are known for water waste, chemicals and energy-sucking equipment, not exactly a model for sustainability.
But technology and a recent push by the industry are making pools greener in a good way.
Operating a pool can be a lighter load on the environment and our pocketbooks.
By changing some outdated equipment, a pool owner could save $350 to $700 per year.
This year, Terry Aubuchon of Stilwell, Kan., made the switch from mixing chlorine with other chemicals to using a salt system to sanitize her backyard pool.
"From a maintenance standpoint, it's so much easier to deal with," said Aubuchon, who works in admissions at Children's Mercy South in Overland Park, Kan. "You just add a bag of salt, and the water feels and looks great."
The salt is converted into chlorine to kill bacteria using a salt-chlorine generator, which costs about $1,400. The old-school way of buying chlorine and other chemicals is $350 to $500 annually, compared to $8 for a bag of salt.
"It eliminates the chemical soup," said Roger Banks, owner of Banks Pools in Overland Park, whose family has been in the pool industry since the 1960s. Still, fewer than half of all pool owners have made the switch to salt-chlorine systems.
Most people who talk to Aubuchon wonder if her pool turns into saltwater like the ocean.
"Not at all," said Aubuchon, who had Dreamscape Pools install the system. "There's only a slight taste of salt."
Roughly a teaspoon of salt per gallon, to be exact. Chlorine in chemical form sends hundreds to the emergency room each year. Salt-based chlorine also is gentler on hair, skin and eyes. Some compare the physical feeling of the water to that of a home water-softener system. Aubuchon says her three teen-agers appreciate the difference.
"There's still a little bit of eye irritation, but that's after swimming for 45 minutes with your eyes open," Aubuchon said.
Salt chlorine also might be gentler on her pool liner. She's on her fourth one in 13 years; the average costs about $3,000.
A downside of salt chlorine is that it will corrode metal faster, so her ladder might rust. However, many pools built now don't use metal and instead use concrete or stone ledges for sitting and to help people get in and out.
Moss is another healthier sanitizing option for pools. Creative Water Solutions of Plymouth, Minn., tapped the water-cleansing power of moss and packaged it in a sort of "teabag" filter.
The moss filter reduces the amount of chlorine needed by up to half, according to GreenBuilder Magazine. More than 99 percent of bacteria in pools live in a protective shield called biofilm. Moss does a better job than chlorine in fighting biofilm, preventing it from forming. This not only keeps the water clean but stops the corrosion and energy loss that is caused by biofilm.
California legislators recently began requiring new, efficient pool products; Energy Star is supposed to address pool equipment this year.
Pumping systems are what keep water in a pool relatively free of dirt, debris and bacteria. Older pumps run nonstop, so it's no surprise pools account for half of an owner's electricity bills.
New variable-speed pumps with permanent magnet motors and digital controls, about $1,300 installed, can save as much as 90 percent in utility costs compared to one- or two-speed pumps with induction motors.
Energy-efficient one- or two-speed pumps are available but should be properly sized to your pool's requirements.
More efficient heaters
If your pool heater is more than 5 years old, chances are a new high-efficiency gas heater could quickly pay for itself in utility bill savings.
"The heaters from 15 or 20 years ago are gas-guzzling hogs," said Terry Wood, owner of Wholesale Pool and Spas, based in the Kansas City area.
New gas heaters produce five times more Btu with less gas. A new one costs about $2,100 installed.
Geothermal heat pumps for pools can save up to 80 percent in energy usage compared to a gas heater, but in some areas gas is preferable because it heats the water more quickly. Heat pumps, about $3,500 installed, can take three to four times longer to heat up but are less expensive to use, about 90 cents per day vs. $6 or $7 per day for gas heaters.
Solar heating systems also are available and heat for free after the equipment is purchased. The drawbacks are that they require space, an area equal to half the pool. Solar pool heaters also require a number of panels, which generate peak output when the pool is often already warm enough.
Hybrid solar systems also are available, and so are advanced solar thermal designs that make it possible to integrate hot water, domestic space heating and pool heating. Prices vary according to property configurations in relation to the sun.
Pools energy use
There are 4.5 million in-ground pools in the United States, which use $1.1 billion to $1.6 billion worth of energy per year. Our nation's residential in-ground swimming pools consume 9 billion to 14 billion kilowatt hours and 36 million to 63 million therms of natural gas each year, resulting in carbon dioxide emissions of about 10 million tons per year -- the equivalent of 1.3 million cars and light trucks on the road per year.
If all residential pools were upgraded to reduce pumping energy by one-third, and all heated pools were upgraded to reduce heating energy by one-third, the total annual savings would be more than $360 million. Carbon dioxide emissions would be reduced by at least 3 million tons.
* Source: Natural Resources Defense Council publication Synergies in Swimming Pool Efficiency: How Much Can Be Saved?