Design Q+A: Natural swimming pools

Cooling off, sustainably.


Daniel Whiting, owner and operator of Next Generation Natural Pools
Native Islander Whiting shared three recent natural swimming pool projects, as well as facts about his eco-friendly business, and how natural pool installations compare with traditional swimming pools.

What is a natural swimming pool?
Natural swimming pools use a biomechanical filtration system designed to create an organic, healthy, and sustainable swimming environment. Using permaculture methods, natural pools use only organic processes and biofilters to give you clear, pure, safe, chlorine-free, and chemical-free water — leaving less waste, and less harm to your health and the environment.

How does it work?
There are two distinct parts to a natural swimming pool: the swimming area and the regeneration zone. In the regeneration zone, water is pumped through the biofilter, where our unique filter media and friendly bacteria work together to remove organic nutrients from the water. This prevents algae and nasty bacteria from being able to grow by starving them of the essential nutrients they require. The regeneration zone can be totally separate from the swimming area, if you want to have it look like a traditional pool. Or you can blend it into the design, like we show in these pictures. It all depends on what the client wants. If they want an “Edgartown-looking” pool and don’t want to look at the plantings, we can organize that.

The swimming zone provides a unique design that blends with the natural environment. The same goals can be accomplished with a concrete-based pool as with a liner, depending on the design and building conditions.

Talk about the role of the natural plantings that surround each site.
The plants that are inside the pool are part of the filtration. With a natural pool, as I mentioned, there’s a swimming zone and a regeneration zone. They are one body of water, but they are separated. The circulation system is engineered to filter the water by drawing it through the plants and the biofilter, maximizing the nitrification process [the process by which bacteria in soil and water form nitrates, which can be easily absorbed by the roots of green plants — an important step in the nitrogen cycle].

What are the benefits that come with natural swimming pools?
Natural swimming pools are a lot more environmentally friendly than traditional swimming pools. It’s not carbon-bombing with chemicals. It’s a biomechanical filtration system that — when designed correctly — can provide clean, safe, clear swimming water without chemicals. It’s good for people, and good for the environment in general.

Are natural swimming pools becoming popular?
They’ve been popular in Europe for the past 20 years, but only started gaining popularity in the states about 10 years ago.

The challenge here is education. I think people’s perception is they just think it’s going to be an algae-ridden, mucky mess. But when you see one in person, you realize it’s not like that at all. The perception is changing, but there need to be more natural pools out there, so people don’t assume it’s going to be a mess.

What’s considered when choosing where to set the pool?
Placement-wise, you want to consider runoff, especially if there are fertilizers in the ground. Soil conditions will dictate how you decide to contain the pool’s water. You can use concrete, or a liner, or a combination of the two, depending on how the soil can handle the structure. But other than that, choosing where the pool goes is really just about what feels natural in the environment.

Explain the role of runoff.
Runoff is the same thing that happens at Sengekontacket. If there’s excess nutrients that get washed into a contained body of water, it’ll unbalance the system. It’s a balancing act with the system. If there’s too many nutrients, the algae will thrive. Any kind of runoff from fertilizers is a concern.

How long does it take to install a natural pool?
Generally, you would try to get the shell in the ground in the winter before it freezes. Then, we come back in the spring to get it all going. The time it takes varies. I think the process is pretty similar to chlorine pools.

On average, how many natural swimming pools do you install in a year?
One per year.

How much does it cost?
It’s similar to solar. There’s a higher upcost, but over time, because they’re pretty much self-maintaining, after three years, it’ll even itself out.

What are common challenges?
You’re creating a controlled ecosystem, and you’re maximizing the nitrification process. You’re putting in all these things to your advantage so you can hydroclean the water using nature’s processes. You’re engineering the pool to work like a machine, even though it’s all natural. The technical design is what I’d say is most challenging.

What materials are used?
There are plants. Different aggregates for plants to live in. And then we bring in a lot of different stones and rocks to naturalize the design. We use local stones when we can, but a lot of the big stones you see around here come from off-Island.

Is anyone else doing natural pool installations?
There are other companies that come here to do them as they’re becoming more popular, but I’m the only local source.

For more information on Next Generation Natural Pools, visit