Combing the benefits of cold water with a sustainable build, a natural swimming pool is a choice that is good for both the environment and your garden aesthetic.
Having heard of the myriad benefits a natural swimming pool brings, not least of which is a light touch on nature and excellent quality of water, I was intrigued to learn more. In conversation with Declan Hassall, owner of Cornwall Ponds, I was educated in the art of achieving a pool requiring minimal maintenance that has the environment in mind.
What are the main benefits of a natural swimming pool compared to a traditional chlorinated pool?
The main two benefits of a natural swimming pool over a chlorinated one are one that it is much better for the environment, encouraging all different types of wildlife; from providing water for birds and other animals to drink, to habitats for amphibians and various other fauna. The flora attracts bees to your garden which, in my opinion, is the most important benefit and something I strongly encourage.
There are also massive benefits to the users of natural pools. Swimming in an unchlorinated pool is better for your skin and for your eyes – we all know after you come out of a chlorinated pool you can feel and smell the chlorine on your skin and sting in your eyes. Coming out of a natural pool makes you feel rejuvenated and is also proven to help and improve your mental health.
What ongoing maintenance is required for a natural swimming pool?
Maintenance on a natural swimming pool is relatively low and all depends on just a few factors. Some pools have more external mechanical filtration then others; some clients opt to have external filtration which removes waste from the pool usually in the form of leaves and debris so it doesn’t build up as sludge at the bottom. So, in these cases the filters will need maintenance now and again when needed, but it’s all very easy to do.
Pools that have skimmers will need to be emptied depending on the amount of leaf fall, mainly in the autumn most days. The surrounding plants will need cutting back in the autumn and some may need thinning out at times… but the main thing is, there’s no need to top up with any chemicals!
Are there any specific environmental conditions that are ideal or unsuitable for building a natural swimming pool?
There are no real environmental conditions that would restrict a natural swimming pool build, however certain factors like leaf fall and the amount of space needed for a pool do need to be considered. However, natural pools can be made in any shape or size, even natural plunge pools which take up less room can be an option. Even leaf fall is not a massive problem, as previously mentioned skimmers can be put in place to remove them from the pond.
How long does it typically take to build a natural swimming pool?
Every natural pool is different and depends on access to the area in which the pool is being made within, the size of the pool, and the landscaping around it. I’ve had builds take just three weeks but also a build that took six months due to the whole pool being covered in rock so that the liner wasn’t visible as well as the installation of hardwood decks, saunas and a firepit. On average though I would say a pool takes around six to eight weeks to complete.
Is there a cost benefit to a natural pool?
I personally think it’s a misconception that a natural pool is cheaper to build than a chlorinated one, as there are a lot of different materials needed in the case of a natural pool. As to the ongoing costs for a natural pool, these are relatively low in comparison as you don’t have the chemical costs to contend with.
Can a natural swimming pool be installed in any size or shape, or are there limitations?
Yes, and no! It’s recommended that if your pool is for swimming that you have a minimum of a 40m2 area, meaning you then need a 40m2 regeneration area as the general rule of thumb for a natural swimming pool is 50% swimming area, 50% regeneration planting area. Shape can be anything you like and designed to suit the garden and area that you are working with. Some people opt for a very natural shape for a swimming and regeneration area while others opt for a traditional rectangular pool. Saying this, we can create thinner or smaller plunge-type pools which can be used in most sized gardens even if it’s just to immerse yourself in and be at one with nature.
How does the initial planning and design phase work for a natural swimming pool?
The initial planning starts with a consultation to find out what sort of pool you would like; we start by determining shape, size, choice of stone or rock, if you want jetty or outdoor showers and firepits and, most importantly in my opinion, what the access is like for material moving and access for plant. Some clients opt for having drawings made to give a rough idea of what it will look like, whereas others give me free reign on design!
Can you explain more about the process of constructing a natural swimming pool?
The process starts with an initial consultation as mentioned above, to find out a client’s needs etc. Once everything is agreed and we have a start date we can commence. The first stage is the set up on site, getting all the plant and as much of the materials needed as possible ready. The dig-out then starts! This is a crucial part and normally takes one to two weeks depending on the size and where the dug-out material is going. Once the dig-out is finished and any footings are completed the next stage is putting the liner in. This is typically EPDM rubber with a heavy-duty underlay underneath.
If any splicing of the liner is needed, it is done at this stage. After the liner is fitted, the fun part begins. Stone is placed in position and we start creating the pool itself; waterfalls and streams can be incorporated to add the tranquil sound of running water. The regeneration section has pipes positioned with pebbles on top of it, not only to disguise it but also to add a substrate for plants to grow in. Jettys, ladders, steps and anything else is also added at this point in the build. Once the build is complete, we then pressure test all the fittings, clean down the pool and when that’s all signed off, we can fill it up. Once full we plant it out and make sure everything is perfect. The final stage is the most important, and that is to jump in!
Can you help with planting schemes once a natural pool is installed?
Yes, I can and it’s one of the parts of the job I enjoy the most! I can work with you to find out what types of plants you enjoy but also advise on plants that will aid the most in terms of filtration and water quality. Plants do wonders in ponds and again attract so much fauna as I previously said to encourage bees into your garden. I personally wouldn’t recommend stocking your pool with fish, as other types of wildlife will thrive a lot more if you don’t. I would recommend as many British native plants as possible, not only in the pond itself but also around it is ideal to encourage as much wildlife as possible and allow frogs, toads, newts, damselflies, dragonflies and all other bugs, beetles and insects to thrive! Some suggestions are yellow flag iris, water forget-me -not, marsh marigold king cup, flowering rush, purple loosestrife and Nyphaea Alba white water lily to name a few. Obviously you can, and we do, include non-natives which can add colour while still providing a brilliant habitat for fauna to thrive.
Can you expand on how water clarity and cleanliness is maintained without chemicals
Different companies and individuals use different methods of filtrating natural swimming pools but the objective is the same; to reduce the amount of nutrients in the water that encourage algae and thus keep the water clear. All natural swimming pools have a regeneration area that is filled with plants, the plants act as a way to absorb nutrient’s, micro-organisms and pathogens. Some people opt for external filtration, with the use of UV clarifiers which kill the algae cells, which is a way of taking out the waste produced by ponds, but does lower the nutrients within.
With natural swimming pool filtration you can have moving bed modules which are a form of biological filtration, they are filled with a Hel-s media that has a settlement surface for micro-organisms of 704m2/1000L of water. Skimmers and intake bays are also used to take out floating debris before it reaches the bottom and so eliminating excess nutrient entering. In addition, rocks and pebbles themselves do a huge amount of filtering.
What are the potential challenges or downsides of owning a natural swimming pool?
I would say there are no downsides to owning a pool, other than the initial financial outlay. They bring a huge amount of joy and wildlife to the garden. The only challenge (and I wouldn’t necessarily call it a true challenge) is making sure you stay on top of maintenance as some pools may struggle with algae and blanket weed. However, with the right amount of filtration and plants this can all be controlled. Even if you don’t opt for a natural swimming pool, having a body of water in your garden, even just a small one, is a brilliant way to help nature thrive. It’s amazing what will find its way to it and what it will do to help your garden flourish.