Eco-friendly approaches to clean pool water

photo of green-treated poolIf all green products did was save our planet, they wouldn't be so darn popular. Fortunately for Mother Earth, eco-friendly practices can make fiscal sense, as well. In 2008, American consumers doubled their spending on sustainable products and services to an estimated $500 billion, according to a survey of more than a 1,000 people by Penn Schoen Berland Associates, a market research firm that studies the green economy.

Savvy retailers of chemicals and sanitizing equipment have been taking advantage of this still-booming interest in eco-friendly products. When it comes to keeping pool water safe and swimmable, current and prospective pool owners have a couple of options to choose from to reduce their carbon footprint.

As Green As You Can Get

For the truly green, there's James Robyn's BioNova natural swimming pools. These vessels, which Robyn actually prefers to call constructed swimming ponds, use no chemicals, like chlorine, bromine or biguanide, or electronic devices like UV sterilizers, ozone, ionizers or salt systems. They save all the resources expended in the production and application of sanitizers simply by not doing it.

"In these ponds, we're not sanitizing, so we're not trying to kill bacteria," says Robyn. "The BioNova ponds mimic a natural wetland. Mankind has grown up on this planet and evolved drinking water from freshwater wetlands that has been clarified and purified the way Mother Nature does it. We're not suggesting you drink the water we provide in our swimming ponds, but you can certainly bathe in it. They're ponds, they're filled with good bacteria, and if you have a pond teeming with good bacteria, it's tough for bad bacteria to get in there and get a foothold."

Design options for these constructed swimming ponds are pretty much unlimited, says Robyn. "You can design the swimming vessel so that it looks like a natural pond or you can design it so that it looks like a formal swimming pool. And then the regeneration zone similarly could be a natural construction so that it looks like a pond, or you could make it into a formal water garden. Mother Nature doesn't really care what kind of shape we contain her in. As long as she has all the things she needs to clarify and purify the water, it'll work."

One thing you need is plenty of space, because the swimming area and the regeneration zone where the purification takes place need to be the same square footage. To better understand what is happening in these constructed swimming ponds, Robyn offers the following explanation: "These ponds consist of deep, middle and shallow water zones. In each of these zones are plants, which help with the cleaning of the pool and create the climate for an ideal mix of microorganisms. These plants are bedded in gravel and other special aggregates, and water from the swimming area is pumped through these zones so that microorganisms and other small life forms become permanently embedded and help clean the water. The basis of this biological cleaning process is the use of plants in connection with a patented eco-friendly biological filtration and hydraulic system. The surface water is cleaned with the help of skimmers and overflow gutters.

"These vessels have a much lower carbon footprint," adds Robyn, "because they don't need chemicals and the flow rates on our filtration are much lower than what they would be on a traditional chemical pool, so there is less energy consumption. We're also building a sustainable ecosystem, so we think we're improving things."

There is some maintenance involved in keeping these swimming ponds beautiful, but not much. "You need to clean out the skimmer baskets, and vacuum the pool or have an automatic pool cleaner," says Robyn. "You need to empty the pump basket and clean the filter periodically, and there are some elements of water gardening involved, like keeping the plants under control and making sure they're living OK. But we don't have anything associated with chemicals, and you can kind of leave these pools alone and they do pretty well all by themselves."

The United States has not yet adopted water-quality standards for these pools, but they do have standards in Europe where there are a number of public natural swimming pools. Robyn adheres to the European standards, which indicate bacteria count parameters. "The standards are very stringent," says Robyn, who is currently looking into the feasibility of converting an existing traditional chemical pool in Edmonton, Alberta, into a natural swimming pond.

Into The Mainstream

While not all prospective pool owners have the space for or interest in a natural swimming pond, many do have an interest in maintaining a more modest carbon footprint. Toward that end, Jon Temple, owner of Tempool in Jacksonville, Fla., encourages clients and builders to use ozone. "It's a great product," says Temple. "There's no chemicals at all involved in it."

In the past, Temple explains, when pool pumps ran for eight to 10 hours a day, ozone really couldn't stand by itself. "You needed a backup sanitizer in addition. But now we're starting to use multi-speed pumps, so it's energy efficient to run your pool 24 hours a day. And this is really a better situation for ozone."

In many cases, says Temple, it's still advisable to have a salt chlorine generator as a secondary means of sanitization. "But with the salt chlorine generator as a backup, you only need to use a small amount of chlorine, at levels like 1 ppm.

"By doing that," Temple continues, "not only are you sanitizing your water very well, you have more-natural water. And by using lower levels of chlorine in the pool, you're generating less byproduct and have fewer total dissolved solids in the pool. And this helps to minimize scaling, because if you have too many total dissolved solids in your pool and a high pH or high alkalinity, which is common in salt pools, those total dissolved solids are going to go into scaling form. They're going to stain the pool.

"To get those stains off, you're going to be using muriatic acid, which has a low pH and low alkalinity, and then you're going to have to dump that pool to get all that stuff out of the pool, and then fill it up with fresh water. That's not good. We want to get away from that. Salt chlorine generators are good sanitizers, but if we can use less salt and have fewer total dissolved solids in the pool, that's the ticket."

Brian Van Bower, president of Miami-based Aquatic Consultants and a founder of the Genesis 3 Design Group, also favors combining these two forms of sanitization. "We have been doing chlorine generation salt conversion with ozone for several years and are big proponents. It would be our preferred treatment for a few reasons. It gives excellent water quality, and most people who use it with any regularity feel like they're swimming without any sanitizer or any chlorine. I think they're relatively user friendly, and the feedback I get from clients is substantially positive. People tell me the water feels soft and silky, and that the water is very eye friendly, which is mostly due to the fact that the pH is relatively neutral."

Another benefit to using ozone with salt systems, notes Bower, is that since you can operate at a lower chlorine level, you're extending the life of the salt chlorine generator's cell because it doesn't have to produce as much chlorine. "Also, ozone is a coagulant so it gathers small particles into bigger ones so you get slightly better water quality."

Bower prefers to use salt systems as the primary means of sanitization and ozone as an aid to reduce the amount of chlorine needed, but then for his indoor pools, he reverses this scenario because he doesn't want to have much chlorine in the room, and ozone works better when there isn't sunlight constantly depleting your chemical in the water. "For these indoor pools, we use a larger, commercial-type ozone system and then a very small chlorine generator or bromine feeder as a backup."

Whatever steps you take to reduce the footprint of the pools you sell, install or service, clients will notice, and those who are trying to tread more lightly on the planet will look to you when it comes time to buy.

Comments or thoughts on this article? Please e-mail [email protected].

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