A natural pool keeps its water clean without chlorine. Next to the swimming area sits a planted regeneration zone, where aquatic plants and biological filtration do the job that chemicals do in a conventional pool. A pump moves the water between the two, and the water stays clear, soft on the skin and free of the chlorine smell.
In the right Cornish garden they look as though they've always been there. In the wrong one they're a disappointment. This page sets out the honest answers to the questions we're asked most, so you can decide whether one is worth exploring.
| Natural pool | Conventional pool | |
|---|---|---|
| Keeping the water clean | Plants and biological filtration | Filtration plus chlorine or another sanitiser |
| Space needed | More: the swimming area plus a planted zone | The pool and its surround |
| Water temperature | Cooler, gently heated at most | Heated to whatever you like |
| Look | Clear but natural, never bright turquoise | Whatever colour the finish gives |
| Upkeep | Less chemistry, more gardening | Regular water testing and dosing |
| Cover | Over the swimming zone only | Over the whole pool |
Water is drawn from the swimming area and pumped through the regeneration zone. Gravel and plant roots trap and break down the organic matter that would otherwise feed algae, and the cleaned water flows back to the swimming area. Some designs add a separate biological filter, which lets the planted area be smaller. There's still a pump and pipework, so the plant room matters just as much as in a conventional pool.
More than a conventional pool with the same swimming area, because the planted zone has to be large enough to do its job. On many designs it adds roughly half again to the footprint. Designs with a separate biological filter need less. We'll tell you at the site visit whether your garden can take one comfortably.
Gently. Warm water encourages algae, so a natural pool will never be as warm as a heated conventional pool. If a warm swim in May matters to you, a conventional heated pool is probably the better choice, and we'll say so.
The plants die back and the water gets cold, so it looks like a still garden pond for a few months. The system keeps running at a lower rate, and there's no need to drain it. Some people love it in winter. Others prefer a pool they can cover and forget until spring.
Different maintenance rather than less. You won't be testing and dosing chemicals, but you will be skimming leaves, cleaning the pool floor, keeping the filters clear and cutting back the plants once a year. It suits people who enjoy their garden. We hand over with clear guidance and stay on the end of the phone.
Usually about the same as, or more than, a conventional pool with the same swimming area. You save on chemicals and some plant equipment, but you pay for the extra excavation, the planted zone and the planting. We'll give you a written figure after a site visit.
Children can swim in a natural pool just as they would in any pool, and many parents like the absence of chlorine. Supervision matters just as much, and the planted zone needs to be kept separate from the swimming area. A natural pool also copes best with a steady, moderate number of swimmers. A pool with lots of children in it every day of the summer holidays is a heavy load for the plants, so tell us how you'll use it.
Yes, over the swimming zone. The planted zone needs light, so it stays open. A cover on the swimming area keeps leaves out, holds in some warmth and adds safety.
Often, yes. Sloping ground, tight access and coastal exposure are common on Cornish sites, and we deal with them on conventional pools too. A natural pool on a slope usually needs retaining walls and terracing, which adds cost. We'll look at the ground and the access before suggesting anything.
Honestly, not always. A natural pool needs more space, the water runs cooler, and it will never be swimming-bath turquoise. It's a living system, and it looks like one. For some people that's exactly the point. For others, a conventional heated pool is the better fit. Tell us about your garden and how you want to swim, and we'll give you a straight recommendation either way.
The best first step is a conversation, ideally standing in your garden. Tell us what you're imagining, and we'll tell you honestly what we think will work, what it's likely to cost, and whether we're the right people to build it.
01872 859558