FEATURES
Recycled Water Feature

by Marcia Passos Duffy
Turning a pool into a pond

Erik Kilk’s pond at his home near Vancouver, Wash., is visited by herons, ducks and at least 12 other varieties of birds, and is home to koi and water lilies. It is surrounded by outcroppings of stone and flanked by a lush growth of rhododendrons, yellow-grove bamboo, a coral bark Japanese maple and a variety of flowers.

Alan Bright’s pool is filled with soil at the beginning of the conversion

The pond, however, had a previous life as a 24-by-16-foot inground swimming pool. Kilk purchased the house with the pool, but did not want to swim in the pool or commit to maintaining it.

In Lake Ann, Mich., Alan Bright owned a pool that wasn’t used after his children grew up and left home. He grew weary of the expense and hassle of keeping up the 18-by-36-foot inground pool. “We had that swimming pool forever—26 years—and with all the kids gone, I was just tired of cleaning it all the time,” he said. Instead of filling it in, he converted it into a pond, complete with a waterfall.

These people are typical of those who might be in the market for a pond feature. Instead of filling in the pool, it is converted into a garden waterscape.

Pool to pond conversion

Converting a pool to a pond is about the same as creating a pond from scratch, minus digging the hole. The problem is that pools are usually rectangular or completely oval, not the natural shape of a pond.

Kilk was stumped for a good technique to make the pool look realistic. A friend suggested filling the pool with PVC sandbags filled halfway with gravel substrate purchased from a local rock quarry.

“I had never done this before,” said Kilk, who is an engineer with Hewlett Packard. “And, I really couldn’t find a how-to guide to take me through the steps,” he said. He gathered information from the Internet and took advice from friends. The project took him five months to complete.

“To be honest, if I could have found a landscape contractor who had done this before, I would have gladly hired him, since it was very labor intensive for just one person,” said Kilk.

Kilk documented his progress on the project on his Web site, www.kilk.com/pond, which also has a question and answer page. The project was also featured in a 2006 issue of “Better Homes and Gardens” magazine.

Photo courtesy of Erik Kilk.
Before the conversion of Erik Kilk’s pool.	Erik Kilk’s pond, which started out life as an inground pool, is home to koi and water lilies.

The biggest obstacle to the pool to pond conversion with homeowners, according to the messages posted on Kilk’s site, is the fear of the effort involved. “Cost and materials are not an issue,” said Kilk, who spent a little over $2,600 on the materials for the project. The most expensive was the liner at around $750, with landscape trees, shrubs and flowers coming in second at $600. What was time consuming was the labor. “I can’t see empty nesters and older people doing the work themselves,” said Kilk. “The idea of having a construction professional who knows how to do this kind of project would be appealing to many people,” he said.

Bright also did the conversion himself, but admitted that he had lots of help from his landscaping and pond workers.

“I had four people working on it full time for two weeks,” said Bright, who owns Waterscapes Unlimited (www.waterscapesunlimited.com). Bright says that the cost to complete a pool to pond conversion is about the same as digging a pond from scratch. He has also dedicated a page on his site, www.waterscapesunlimited.com/residential-pooltopond.php, to document the conversion.

“I would say it would cost the homeowner about $8,000 to $10,000, depending on the pool size,” said Bright. His pool conversion included a 75-foot stream cascading down the hill and ending with a waterfall feature. The shape is about the same as the original rectangular pool, but to make it look less pool-like, he added plant pockets alongside a 4-foot-wide peninsula that juts out into the middle of the water (with the deepest end no more than 3.5 feet). “The process is really like building a regular pond, except that the hole is already dug,” said Bright.

Biological filters for low maintenance

In a typical pool to pond conversion, homeowners often wonder if they can reuse the pool’s pump and filter for the pond. They cannot, and should not. “Pond water is more ‘gunky’ than pool water, with leaves, twigs, bugs and dirt that will quickly clog up any pool filter—that would make the pond even higher maintenance than the pool,” said Kilk. “Plus, pool filters are very powerful, costly to run and are noisy.”

Bright used pumps to move the water to the top of the hill and standard pond biological filters to clean it on its way down. He also added two skimmers in the shallow end of the pond to skim debris off the surface, keep organic waste down and maintain the pond’s cleanliness. “The pond doesn’t have to be pristine, like a pool,” said Bright, “but you want it clean enough to keep the fish and plants alive.” This method keeps the pond clean and reduces maintenance and cleaning to once or twice a year.

Kilk opted to build his own filter using the principles of aquarium filters, except the gravel filter was external to the pond and incorporated a “vegi-filter” concept that included plants. The water percolates up through the gravel and plants, and then gravity brings the water back to the pond via a spillway.

The homemade technique worked for Kilk, who said he only needed to clean the pond once a year. “If it’s done right, you shouldn’t be cleaning a pond every week, that’s as bad as a pool,” said Kilk.

Kilk says the demand for pool to pond conversions is out there. “I don’t think pools are a selling point in a home,” said Kilk, who recently sold his home and said the pond was a huge selling feature. “The pool would have definitely been a negative.”

Bright’s pool to pond conversion has not upped the demand significantly for his new specialty, adding that the downturn in the economy may be a factor.

“It’s a psychological hurdle with the family to make a swimming pool into a pond—our grown kids are still complaining about it,” said Bright, “but I don’t miss it at all.”

Marcia Passos Duffy is a freelance writer from Keene, N.H.