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Design #6

The Natural Swimming Pool

Client: The family
Location: Finca Florecer
Start Date: January 2015
End Date: January 2017
Design Process: S.A.D.I.M.E.T.

The site is very exposed from all sides. There is no wind break from the prevailing north-west winds. It is located at the top of the ridge, with two valleys falling away to the west and to the south. To the west there are spectacular views of the Ebro river valley and Els Ports mountain range. To the North here are views to the Cardo mountain range. The house, workshop and general living areas are situated to South-east. There is good access to this area with the main access road and driveway on the north-east side. In the past there had been a wildfire which was contained on the ridge before getting out of control. The area in question is comprised of two terraces. The top terrace is wide and open,below and to the south, the second narrower terrace. Both these terraces have very little vegetative growth due to the lack of soil.

Natural Swimming Pool  proposed site .jp

Plants, shrubs and trees:

The site location is dry with very few plants growing on it. The olive trees have died off on the main trunk and are just suckering (regrowth from base). There are no shrubs or herbaceous growth. The most prominent plants are a few species of grasses, couch grass and a type of sedge like clumping grass, wild annual and biennials self-seeding plants.


There is approximately 20cm of soil before hitting bedrock at the most 40cm in patches. The quality of the soil is a poor silt/sand with no humus and a lot of stones. There is only one composition and that is subsoil. The soil type is alkaline.


Very few to be found. No earthworm activity. A few woodlice and some black beetles.


The area is very exposed to the wind and the sun. Flat land at the top of a ridge.


The first question to ask is:

What is a Natural Swimming Pool (NSP)?

It's a pool that imitates a natural source of water such as pond, lake or river, to produce a swimming pool that is free from chemicals,

adds biodiversity and needs little maintenance.

How do they work?

The natural swimming pool is divided into two parts (sometimes two pools), the Swimming Zone and the Rejuvenation Zone. The Swimming Zone is self-explanatory as in, this is the area where we can swim. The second zone, The Rejuvenation Zone is the area where all the work takes place. It is the bank of the river or the margin of the pond, it's the EDGE! Here is where water flows in a light current through carefully placed marginal and aquatic plants which clean the water and create a natural ecosystem.

For the design to work there are a few rules that have to be followed:

  1. Size... In hot countries the Rejuvenation Zone must be equal to or greater than the total water surface area in the Swimming Zone. In colder climates this can be reduced to about 30% of the total surface area. The actual size of the pool is up to you, but the ratio must be kept.

  2. Depth.... The depth of the pool is very important. Water has thermals, like the air, using different depths can generate these thermals, circulating the water on its own. It is also important for the protection of the living organisms and micro-organisms. At the depth of 2 meters living organisms are protected from the cold of the winter and direct UV rays in the height of summer (which can penetrate water up to 80 cm deep).

  3. Plants.... The plants need to be from the three kinds of water plants associated with natural water systems; marginals and semi-marginals, such as reads and rushes. These filter the water and remove contaminants and nutrients. Floating Plants, such as water lilies, which provide shade and protection from UV rays. Oxygenating plants which absorb nitrates and phosphates and reduce the rate of algae growth.

  4. Aquatic life.... apart from the insects, snails and amphibians which ensures a healthy system (many of which will find their own way into your pool), the essential creatures are the micro-organisms or Daphnia which are an important food source for the other creatures in the pool, but keep regulation of the nitrates, phosphates and phytoplankton. Fish should be kept out of your NSP due to their large consumption of these essential organisms and their waste (poop) which contains high amounts of nitrates. It is best to keep them in a separate fish pond or your aquaponics systems where all their wastes can be used in a much more productive way.

Personal Wants and Needs:

For as long as I can remember all I wanted was my own swimming pool. When I first arrived on my land, the first thing I wanted to build was a pool, but having no access to a water supply was a bit of a spanner in works...

As my values and ethics have developed to be more harmonious with the environment, there was no way that I wanted a conventional pool system, that is only useful for one purpose: for people to swim in, and take so much embodied energy to maintain.

I would have been happy to swim in a pond but when I found out about natural swimming pools, a better solution was found. A swimming pool that could sustain itself, not use chemicals, not use huge amounts energy to run it, be beautiful and work with nature was just up my street. The design needed to take into account not just my own need but also the needs of my family, friends and guests. Speaking with my daughters made me look at the pool with different eyes. I did not mind swimming with plants but my eldest daughter did not like this idea, while she did not mind the plants being next to the pool but she did not want plants surrounding the swimming area. This reminded me of when I was a life-saver, and part of our training was the most terrifying scenario of rescuing someone from vegetative growth under the water surface, which could wrap around your legs, the more you struggle the more you become entangled. So no plant around the edge!

I was happy to make more definable swimming and rejuvenation areas. My youngest daughter, although she can swim is not a strong swimmer. I would need a shallow end where she would be happy to play around in water which is not out of her depth. This would also be important for my friends who have small children.

While talking to one of my volunteers another issue with mainstream pools came to light. She had eczema, which meant that she could not use normal chemically cleaned swimming pools. From experience I found that I did not enjoy swimming in chlorine pools, the sore itchy red eyes, the dry skin and the smell. Swimming in natural water is soft, and a lot more enjoyable. Being able to offer this system to guests and friends, gives people with skin problems a holiday they would not normally be able to have.

Another one of my wants is to be able to swim lengths. I love to swim. Having a pool that I would not be able to swim in, then I might as well have a hot tub. The pool has to be long enough to comfortably get in good few strokes. This means the pool had to be no shorter than 8m at one length.

The thought of swimming amongst nature is a lot more exciting and will make the area more fun to be around in all the seasons not just summer.

Key Wants:

  • Separate swimming pool to rejuvenation zone

  • Enough length to swim in

  • Shallow area for small children

  • Good cleaning solutions, cleaning without chemicals

  • Low energy costs

  • Easy maintenance

  • Secure fencing and gates all-round the accessible parts of the pool.


S.M.A.R.T Goals


  • Size of site needs to support Swimming Zone and Rejuvenation Zone

  • Use natural formation of the site

  • Good access to swimming area but secure enough to keep out wandering, unsupervised children.

  • Use pool for water collection from kitchen roof, until house is complete and then harvest roof-rainwater


  • How much can I do myself?

    I can do a large amount of the work myself and with volunteers, but I would prefer to contract out the main structural work

  • What do I need contractors to do?

    Main structural wall, needs to be built quickly and in one go

  • What is my budget?

    I have enough money to pay for contractors and buy material.


  • What can I use from the area? Local stone

  • Help from volunteers

  • Materials : Building suppliers

    Local quarry

    Local area


  • How much work can I do myself and what do I have to get help with?

    Any regular building work I do not feel comfortable doing. The stone work I am happy to do myself.

The hard-graft, I will share the load by working with volunteers


  • First stage to be completed by summer 2016. Main pool area

  • Second stage completed by summer 2017. Surrounding area

  • Third stage: to be completed after house extension ?





Swimming pool

Concrete blocks, concrete, rebar, impermeable paint, dry stone walls, skimmers, plumbing, fencing, water, wildlife, sheltered terrace

Rejuvenation zone

Concrete blocks, concrete, clay, rebar, stones (large), gravel 20mm, irrigation, inspection tank, water/marginal plants, drystone walls, earth, terrestrial plants, frogs, toads, wildlife habitat, hedging and/or fencing.

Sun/shaded patio

Pump, plumbing, filter, stones, drystone wall, steps, shade, patio stones. sun loungers, fencing,

Water filtration


Pump/filter system

Inspection boxes, 150 ltr tank, metal mesh, felt, stopcock, plumbing/attachments, pump, irrigation pipes, 20mm stones


marginal plants, aquatic plants, micro-organisms, water.

Wind break


Stone, earth.


Wooden planks, wooden posts, pallets,


Roses, climbers


Roof/rain-water Harvesting

Gutters and PVC pipes



Wildlife habitat

Rejuvenation zone

Water, stone outcrops, stone walls, water plants, marginal plants, terrestrial plants,

Erosion Prevention

Stone walls

Concrete blocks, concrete, rebar, stone, earth, plants.

Food production

Aquatic Vegetables

Water chestnuts, taro, water-cress.



Wooden planks, wooden posts, chicken wire,


Wood, locks and catches.


Roses and spiky plants



Permaculture, water-plants etc.


Swimming pool, patio area, view.

NSP Ideas plan.jpg

When I observed, interacted and considered all the factors, this area was too poor to planting on. It was dry, barren and wind swept. But due to its size and situation; close to the house, flat land and good views, it made the ideal site for the pool.

Although I am not following the rules of Key-line Design, the addition of the pool will have a positive impact on this area, adding diversity to an otherwise neglected and useless area.

Efficient Energy Planning

Within the design itself I will be using the lay of the land to determine the shape of the pool, following the patterns of the original terraces (which are built on contour) will determine the size and shape of the pool. The top area is made up of two shallow terraces, the first terrace is large, flat and shallow with a slight slope which would be perfect for the marginals, The next terrace falls away a little deeper and would be the area for the oxygenating plants and also deep enough for the water lilies. These terraces will define the size and shape of the Rejuvenation Zone. The third terrace is 1 ½ meters lower than the one above with exposed bedrock dividing it from the top two terraces. This is long and thin which would make it perfect for the Swimming Zone.

Also using the shape of the natural land fall means no digging through bedrock needed , it can be above ground pool that fits into the landscape, saving a lot of energy and eliminating the need for large machinery.

Diversity and Edge Effect

By planting the taller marginal plants around the northern edge of the Rejuvenation Zone would give a wind break to the rest of the pool, and adds to the diversity that theses edges can create. Integrating the plants in the rejuvenation zone with the pool, will make the pool look more natural and apart from using the plants as a natural water filter (small and slow solutions), it will attract a whole new range of biodiversity to the farm.

Each Element Performs many functions

I will incorporate plants which have more than one function, for example, horse tail which can be blended into a tea and used as a leaf sprayed on fruit trees to strengthen and build up cellulose, oxygenating weed to activate compost, or reeds and rushes which make good mulches, producing no waste only yields. The pool will function as a rainwater collection tank which will be used to irrigate the land.  

Relative Location

Siting the pool close to the house will allow water to be collected from the roof and its position at the top of the land means the water can be used to irrigate the land below. The pool will be located with easy access for both the household occupants and the cabin guests but giving privacy to both parties. The view from the pool area has unadulterated views of Els Ports mountain range giving you a natural setting to relax in.

Energy Cycling

There is nothing better than sitting by the pool at the end of a day listening to the buzz of nature and watching the sun go down over the mountains.

NSP Design.JPG
Final design
NSP Elevation.jpg
NSP filtration system and pump.jpg
Filter Chamber

Stage 1. February 2015 – May 2015

  1. Marking out the pool and defining size within the parameters of the terraces

  2. Dig lower down terrace to bed rock

  3. Build up lower (swimming zone) retaining wall using shuttering to hold in concrete and steel

  4. Add drainage pipe to lowest level of pool

  5. Poor concrete pad at lowest point of pool to help drainage and cleaning

  6. Bring retaining wall up to level and finish off with swimming-pool blocks and steel

  7. Dig out the rest of the perimeter of the walled area down to bed rock

  8. Build wall round to enclose pool area

  9. Fill in corners to create curved edges

  10. Render wall with water retaining cement

Although I had made good use of the digger when digging out the Japanese bath-house for dig-out the bottom terrace area that would be, in time the swimming zone. I had wanted to dig-out the rest of the rejuvenation zone by hand, as it would be following the original terrace walls that followed the contours of the land.

I was not confident to build the retaining walls myself so contracted out the dirty/hard work to a builder friend of mine, Doc. Although this was a very unusual project for him to get his head around he followed my design and gave me good advice to areas that were in his field of expertise.

It was his idea to shutter the first stage of the wall as the ground was so uneven and would make block-work difficult, this saved a lot of messing about and money.

It was also Docs idea to put a concrete pad down in the lower half of the swimming area as this would help give strength to the wall and make the drainage better.

When I pointed out to him that I wanted to curve the corners of the pool as these are the weakest points of stress and should be taken out of any water holding container, I was pleased to educate him for once.

Stage 2. May 2015 – June 2015

  • Build up lower outer wall using dry stone wall technique

  • Along the wall to north-east (at the highest point of the land) add a drainage channel to take excess rainwater run-off away from site.

  • Build dry stone walls all round outer perimeter of the pools retaining wall

  • Clean soil from the bed rock in Swimming Zone

  • Paint bedrock with 3 coats of sika 107 to make rock watertight

The block-work was done efficiently and quicker than I had expected. In just two months the shape of the pool was complete. Before Doc left, I asked him for one week more work, and the use his van to bring me rocks from my neighbours land to build up the dry-stone wall on the south facing side of the pool. Eventually Doc was allowed to leave and I was on my own to clean off all soil and seal the swimming pool area with 3 coats of sika 107.

I finished off most the dry-stone walls around the outer edge of the retaining block-work.

The north-east facing wall was at the highest point of the land and could have been prone to waterlogging when we had our seasonal heavy rains, here I decided to add a drainage ditch to allow excess water to run away from the site.

We had to wait for the sika 107 to cure for 3 weeks but then we were free to fill the area and check for water retention. The best part of this stage was getting to use part of the pool during summer.

Stage 3. June 2015 – October 2015

  1. Remove soil from the rejuvenation zone

  2. Remove olive tree from centre of rejuvenation zone

  3. Remove all soil from bedrock and clean to identify cracks and fissures

  4. Remove central terrace wall

  5. Seal bed-rock under central wall area with sika 107

  6. Rebuild central terrace wall with clean stones and rock. Retained from original wall

  7. Cement capping stones to central wall

  8. Build steps into swimming area

  9. Round off the edge between retaining wall and bedrock and fill fissures with cement

  10. Paint perimeter wall and the first 30 cm edge of rejuvenation zone with Sika 107, to seal

  11. Add capping stones to top of the wall all around the pool and cement them in place

I started by digging out the Rejuvenation Zone and used some of the soil to fill the gaps between the exterior drystone wall to create planting beds surrounding the pool. The rest of the soil was removed in buckets and stored for future use.

New willing volunteers in the shape of Camille and Julie (Wwoof June 2015), came to help for two weeks. I estimated it would take 3 of us one week to clear the rest of the soil out from the Rejuvenation Zone, but the heat of the day, work slowed down considerably and those two weeks were taken up with little else but digging and shifting the soil to a slowly forming mound just out side of the pool.

Cleaning up the bedrock felt like an archaeological dig, every bit of soil was removed to expose any fissures in the rock. The fissures were cleaned, filled with cement and painted over with Sika 107.

The edges between the walls and the bedrock around the pool were smoothed off with cement and painted with Sika to help retain the water. But the majority of the bed rock was left exposed.

The next step was to take out the central terrace wall. As this wall had originally been a retaining terrace wall, it only had one face and was held together with a lot of earth. I also needed to waterproof under this wall as the clay would not cover that area.

Retaining all the stone and separating it out into sized piles helped a lot when it was time to reconstruct. I had a little help from the rain to wash the soil from the rocks and help from my friends nephew, Jimmy, to reconstruct the wall. Jimmy was very proud by the finished product and went home with the new skill of dry-stone walling. The top stones were cemented into place as this wall would have a lot of use, either to be sat on or walked across as a bridge to the deep-end of the swimming area.

It had been impossible to find a nursery (aquatic or otherwise) in Spain that stocked more than 3 – 4 water-plants. In the end I ordered them in England from Paul Bromfields Aquatics. The only Aquatic nursery that had every plant I on my list. Collecting them in England after my AET course in August 2015 and then taking a week to drive back home to Spain, these plants had to survive in a box wrapped in plastic bags, I did what I could to help them during the journey: always parking in shade and opening the bags as to let as much air circulate around them as possible. It was risky but, it worked out and they all survived.. I was quite amazed at how hardy these plants were, seeing as I had not treated these plants kindly from the start. When I got home, my friend Binky, had come over for a day of potting up some 150 plants, but first, as I had not bought proper aquatic planting baskets, we needed to drill hundreds of holes in the side and bottom of regular pots. These pots of water plants were stored in the little bit of water left in the swimming Zone on a couple of pallets.

Looking back think September was probable the hardest time on the project. I was on a roll, but my volunteers seemed to be overwhelmed by the size of the project. I had to stop work on the pool when my volunteer Neil, from Australia, was here as he had back problems and could not do heavy lifting. Not wanting his skills (good at woodwork) to go to waste, instead we started to design the chicken house, a job that suited his needs and skills a little better.

The arrival of Lisa from the UK and a young French couple, Cami and Remi in October meant work could focus on the pool again and we threw our backs into cementing the capping stones to the wall.

The capping stones that I had been collecting from wherever I could find them on my journeys out and about, always stopping when seeing a nice flat stone on the side of the road. It became a bit of a mission for me to not come home without at least 3 huge stones in the back of my car each time I went out. The steps to enter the Swimming Zone were next. Helped by Lisa, Cami and Remi, they were completed in no time, it would act as a barrier between the Swimming Zone and the Rejuvenation Zone.

Stage 4. November – December 2015

  1. Fill rejuvenation zone with 40 tonnes of clay and spread to 40 cm thick over bed rock. and saturate with water

  2. Mark out and build up interior terraces with rocks for different levels of marginal plants

  3. Fleece layer on top two internal terraces in Rejuvenation Zone

  4. Build up walls to retain 20 mm stones and drainage pipes

  5. Add 40 mm diameter washed stones to all terraces and to cover fleece

  6. Lay 110 mm drainage pipe and inspection box for inlet of water

  7. Add more stones to cover drainage pipe

  8. Lay more fleece to protect drainage pipes from plant roots

  9. Top up with stones to 15 cm deep

Cami and Remi wanted to stay on for another week, but little did they realize how hard it would be to move 40 tonnes of clay into the pool. Even though we built a ramp up the east facing wall, allowing the lorry to dump the clay over the edge into the Rejuvenation Zone, it was hard going as the clay was heavy. When they left and it was then down to me to shift the last of it. It was back breaking work!

My next, volunteers were Maddie and Natalie from USA (Nov 2015). We had the less strenuous job of marking out the different levels for the water plants. Deep water for the lilies and yellow flag water iris, 30 cm depth for the deep marginals and graded depths for the shallow marginals.

Originally I had planned to gently slope this area, similar to a river bank, but the terracing made more sense and showed me where the different types of water-plants (deep water, marginals, semi-marginals) would fit into their rightful space. It was also in keeping with the environment around.

When were happy with the shape and size of the terraces, marking them out with rocks and making each terrace level, we lined the top two terraces with fleece. With the help of a neighbour Piote, who was very good at lifting the very big rocks! We created internal terrace walls to hold back the layer of 20 mm stone which would be the next steps to the filtration system. On top of the fleece, we laid out the purpose made drainage pipe. Around theses pipes we laid a layer of 20 mm grade washed stone and then added another layer of fleece to protect the pipes from root invasion and blockage. This pipe would allow the in-flow of water to circulate under the plants. Where the plant roots could draw up the water and filtering out all the nutrients and then circulation clean water back into the pool. On top of this we added another 20 cm of 20 mm grade stone. At the highest point of the pool and connecting all the drainage pipe is an inspection tank and the inlet pipe from the pump.

With all this done, we then had a little time left to make the skimmer for the Swimming Zone. I had bought 3x 1m regular drainage channels which was connected to the pump house by 90mm pipe. The over-flow from the pool would come into this channel, all the large bits of floaty stuff (leaves etc.), would get caught on the grill and the smaller stuff would be filtered out by a fleece filter in the pump house.

In December 2015, Petra from Germany came to visit, we had the fun job of trying to plant numerous pots of plants into scrabblely gravel.

I was going away for a week over Christmas and as I did not have the pool totally filled up during the time of planting, I used irrigation pipe to keep them moist. I was surprised to see how, water from this trickle system started to fill up the pool in just a few days.

Stage 5. January – April 2016

  1. Plant water-plants

  2. Finish the skimmer

  3. Build pump house

  4. Connect pump to skimmer (inlet) and inspection tank (outlet)

  5. Build up sunbathing terrace and steps to pool

After the Christmas holiday I carried on building up the external walls around the pool, filling in-between the blockwork and the dry-stone wall with soil, which would then be planted with roses to create a living barrier to stop people climbing into the Rejuvenation Zone.

In March, Eve and Carman from China came for a week, with their big smiles, large hearts and a willingness to help build the

sunbathing terrace.

The skimmers pipework and filter were to be on the outside of the pool beneath the sunbathing terrace, This meant the terrace had to be built to the same level as the pool edge. Taking the rocks, soil and gravel from the ramp that was used to help the lorry unload the clay and stones into the rejuvenation zone, Eve Carman and I started to build up this area.

At the start of April, Petra came back after finishing her PDC in the south of Spain. Moving on to the skimmer, we started on the pipework that would connect the skimmers overflow channel, to the water filtration system and pump. This was to be a water-butt which would hold a basket containing fleece, which would take out any small leafs or larger particles (that had got through the drainage channel grate in

the skimmer), before the water was fed through the pump up to the inspection box on the top terrace in Rejuvenation Zone, to start the flow through the plants again.

Running out of material for the terrace, my next volunteers, the incredible, Jonny and Celine were up and ready to cart wheelbarrows of rocks, stones and earth from my neighbour's land, to get the terrace up to height and then some really big rocks which we had selected and saved during the demolition of my neighbours terrace, to make the steps up to the terrace and the pool.

Finally all building work was finished. Just the filter and pump was left to do. Phew!!!

Volunteer time line:

Camille and Julie, June 2015

Jimmy, July/August 2015

Binky, september 2015

Neil,(chickens) September 2015

Lisa, September/October 2015

Cami and Remi, October 2015

Maddie and Natalie, November 2015

Piote, November 2015

Petra, December 2015

Eva and Carman, March 2016

Petra, April 2016

Jonny and Celine, April 2016


The maintenance of the pool should be very easy.

Every day during the summer clean out the skimmer from leaves and other larger debris. Change and clean out fleece from filtration system, to remove algae and debris that got passed skimmer.

Winter maintenance involves removing dead or over grown plants to use as mulch or as compost activator.


What went well and what was challenging?

This is a page from my diary at the time of finishing the pool. It is interesting to remember how I felt at this time. I sound very tired!

“After a year of constant work I have almost finished. It has been a hard and sometimes worrying slog. I have had some amazing support from friends, but the help I have received from Volunteers has been unbelievably invaluable”.

Each one of them was only there for a short period of the building process, but at every stage it has felt like a mile stone completed.

A few things have changed from the original design. Mainly the interior of the Rejuvenation Zone, where I had thought to bank the stones into the pool. In the end I used a lot more clay than I first calculated. When the price for the clay came in, it was half the price of 20mm stones so I over doubled the depth of the clay layer to 40 cm. In retrospect this was a better move as I had not sealed the bedrock in this zone and the clay was acting as the impermeable barrier, the deeper the better. By this stage I was running out of funds anyway, so I was looking for ways to save on cost, clay is an unwanted by-product in the quarry and I only had to pay for the delivery costs.

Another design change was to terrace the rejuvenation zone instead of just banking the stones, this seemed more in-line with the general area and meant that I could use locally sourced stones (from my neighbours land) and I could buy in less 20mm gravel. This caused a little bit more work but was worth it in the end as it defined the planting areas and allowed access to all parts of this zone via the walls and made lots of little nooks and crannies for the wild life which will inhabit the pool itself.

Since filling the pool, I have discovered a few leaks, one major leak is in the seam of the bedrock from the rejuvenation zone, but this seems to have slowed since the clay is doing its job and hopefully penetrating the seam, filling it and making it water tight. There is also a leak in some of the capping stones, which have not been set in properly. This will have to be rectified before the pool can be filled to the top and the plumbing work installed.

At the moment I am plagued with mosquito larvae but will have to wait for the frogs to start spawning to rectify this, I do not want to put fish in the system as I would probably never find them again.

I am pleased to say I have recovered and the pool is now the most relaxing place on all the land. It worked even without the pump and filtration system working. (In fact it worked so well without them that it took another two years until I did get it working!).


What are my next achievable steps?

Review November 2016

I scraped the idea of using a water-butt for the filtration and pump housing, instead I rendered and sealed the brick-work that the butt sat in. I installed a ball-cock to keep the water-level up during summer and overflow pipe just in case. I made a wire basket with a fleece lining to collect smaller particles coming from the skimmer and a 12v caravan water pump connected to two 70 watt solar panels.

I had big problems with this pump. It was a self priming 12 volt caravan pump which would not prime, I struggled with it for sometime before giving up completely and buying a 40 watt pond pump which I now have on a timer, set for two hours a day during the height of summer, which works wonders.

At the end of the day the best filtration system seems to be a regular swim or a few kids to stir things up, after an hour, it all settles to the bottom and you can let it out the drainage pipe.

Review 2017

As time had past I realised that the terrace was only big enough for two sunbeds and there was a lot of unused space around it, which was filling up weeds. In march 2017, I decided with the help from a different Jonny (UK), Ben and Luce (FR) to make the sun-bathing terrace bigger.

By the end of June with help from Chloe and Joe, (helping along side, another Joe, from America), the Sunbathing terrace was completed with stone paving and a shade made out of the left over rebar from the NSP build. Just in time for a party!!!

What are my long term goals?

  • Open the pool to cabin guests

  • Help others who are thinking of building a natural swimming pool

  • Enjoy my summers sitting by the pool watching nature busily working to make a better environment for all!


Water Plants

Marginal Aquatic Plants:

Zone 1

1. Acorus Calamus – Sweet Flag.

  • Hardiness zone: 4-11.

  • Water depth: 0-7.5cm

  • Height: 0.6-1m

  • Comments: winter dormant.

  • Plant in 20ltr pot.

2. Botomus Umbellatus – Flowering Rush.

  • Zones 3-11.

  • Water depth: 8-13cm

  • Height: 1m, flower 1.5m

  • Comments: needs rich soil.

7. Cyperus Alternifolius – Umbrella Palm

  • Hardiness Zone: 7-11

  • Water depth: 2.5-15cm

  • Height: 0.3-1.5m

  • Comments: plant in 20ltr pots.

8. Cyperus Longus – Sweet Gallingale

  • Hardiness zone: 6-10

  • Water depth: 2.5-15cm

  • Height: 150cm

  • Comments: Grow in 20ltr pots, edible roots.

3. Calla Pulustris – Bog Arum

  • Hardiness zone: 3-6

  • Water depth: 5cm

  • Height: 15-30cm

  • Comments: All parts are poisonous when fresh but the rhizome is edible when dry.

4. Canna Lilly

  • Hardiness zone: 9-11

  • Water depth: 2.5-25cm

  • Height: 1.2-1.5cm

  • Comments: naturally a terrestrial plant they can slowly be naturalised into deeper water.

5. Carex Muskingumensis & Riparia Bowles Golden – Grey Sedge

  • Hardiness Zone: 3-7

  • Water depth: 0-7.5cm

  • Height: 38cm

  • Comments: needs rich top soil in 4-8ltr pots, clump forming in half shade to sun.

6. Cotula Coronopifilia – Brass Buttons

  • Hardiness zone: 6-9

  • Water depth: 0-5cm

  • Height: 0.1-0.5cm

  • Comments: plant in full sun. All the plant is good for dye, Golden yellow.

9. Equisetum Japonicum – Barred Horsetail

  • Hardiness zone: 4-11

  • Water depth: 0-5cm

  • Height: 1.2m

  • Comments: can be invasive Plant into 8Lt pots with hessian linning.

10. Houttuynia Cordata Variegata

  • Hardiness: 6-10

  • Water depth: 2.5-5cm

  • Height: 15cm

  • Comments: pot in 4lt pots, good ground cover around pond edge.

11. Iris Versicolor Kermesina

  • Hardiness: 7

  • Water depth: 5-10cm

  • Height: 60-75cm

  • Comments: blue flag Iris, clump forming.

12. Iris Laevigata, Gerald Darby

  • Hardiness: 7

  • Water depth: 5-20cm

  • Height: 120cm

  • Comments: plant 5-7.5cm below soil level in lime free soil.

13. Iris Lousisiana, Black Gamecock

  • Hardiness: 7

  • Water depth: 0-5cm

  • Height: 80cm

  • Comments: Deep purple flower heads.

19. Saururus Cernuus – Lizards Tail

  • Hardiness: 4-7

  • Water depth: 2.5-15cm

  • Height: 30-60cm

  • Comments: plant in 8-20ltr pots

14. Juncus Effusus, Spirallis – soft rush

  • Hardiness: 4-9

  • Water depth: 2.5-15cm

  • Height: 45cm

  • Comments: Plant in 8ltr pots

15. Juncus Effusus – soft rush

  • Hardiness: 3-8

  • Water depth: 2.5-15cm

  • Height: 30cm

  • Comments: plant in 8ltr pots

16. Lobelia cardinalis, Cardinal Flower

  • Hardiness: 5-11

  • Water depth: 2.5-7.5cm

  • Height: 60-122cm

  • Comments: plant in 4lt pots

17. Myosotis Scorpioides, water forget-me-not & mermaid

  • Hardiness: 3-10

  • Water depth: 0-5cm

  • Height: 10-60cm

  • Comments: creeping underground roots forming dense colonies

20. Scirpus lacustris albescens – stripped bulrush

  • Hardiness: 5-11

  • Water depth: 0-20 cm

  • Height: 1-2m

  • Comments: plant in 8-20ltr pots

21. Sisyrinchium Californicum & Angustifolium

  • Hardiness: 6-10

  • Water depth: 0-5 cm

  • Height: 30cm

  • Comments: can self-seed

22. Stachys Palustris – wound Wort

  • Hardiness:

  • Water depth: 0-10 cm

  • Height: 1m

  • Comments: highly invasive. Good wild life attractor, especially bees. Tubers can be eaten raw or cooked and have a nutty flavour.

18. Potentilla Palustris – Marsh cinquefoil

  • Hardiness: 3-7

  • Water depth: 0-5cm

  • Height: 20-150cm

  • Comments: Leaves can be used as a tea substitute, root is an astringent and can be used to treat dysentery and stomach cramps. Flowers make a red dye.

Zone 2

23. Caltha pulustris – Marsh marigold.

  • Hardiness zone 2-6.

  • Water depth: 10-13cm

  • Height: 30-45cm high.

  • Comments: spring colour Yellow, dormant in winter, likes shade

24. Canna Lilly

  • Hardiness zone: 9-11

  • Water depth: 2.5-25cm

  • Height: 1.2-1.5cm

  • Comments: naturally a terrestrial plant they can slowly be naturalised into deeper water.

25. Cyperus Alternifolius – Umbrella Palm

  • Hardiness Zone: 7-11

  • Water depth: 2.5-15cm

  • Height: 0.3-1.5m

  • Comments: plant in 20ltr pots.

26. Cyperus Longus – Sweet Gallingale

  • Hardiness zone: 6-10

  • Water depth: 2.5-15cm

  • Height: 150cm

  • Comments: edible roots.

27. Iris Pseudacorus – Yellow flag & Alba

  • Hardiness: 7

  • Water depth: 35-38cm

  • Height: 1-1.5m. Spread: 1-1.5m

  • Comments: happiest in deep water and slightly acid soils.

29. Sagittaria Latifolia – Duck Potato or lance-leafed arrowhead

  • Hardiness: 6-11

  • Water depth: 0-30cm

  • Height: 30-50cm

  • Comments: plant in 8lt pot.

28. Pontederia cordata, pickerel weed

  • Hardiness: 4-11

  • Water depth: 2.5-45cm

  • Height: 45-60cm

  • Comments: plant in 20ltr pots, can be immersed, submerged, floating or creeping.

Zone 3, Submerged Aquatics

30. Ceratophyllum Demersum – Hornwort

  • Hardiness:

  • Water depth: free floating

  • Height: 30-60cm

  • Comments: Oxygenator. Over winters at bottom of pond.

33. Hydrocharis Morsus Ranae – Frogbit

  • Hardiness:

  • Water depth: floating

  • Height: Surface

  • Comments: slow to come back in spring.

36. Nymphaea Assorted

  • Hardiness: 5-10

  • Water depth: deep

  • Height: surface

  • Comments:

39. Arundo Donax ‘variegated’ - Giant Mediterranean rush.

  • Hardiness Zone: 7 – 11.

  • Hight: 1 – 2.4m

31. Eichhornia Crassipes – Water Hyacinth

  • Hardiness: 10-11

  • Water depth: free floating

  • Height: 30cm

  • Comments: Highly Invasive, needs regular control. Good for taking up nutrients from water. Excellent source of biomass.

32. Elodea Canadensis – Canadian pond weed

  • Hardiness:

  • Water depth: deep

  • Height: free floating but best anchored to bottom

  • Comments: Oxygenator. Excessive sunlight can kill it.

34. Lemna Minor – Duck weed

  • Hardiness:

  • Water depth: floating

  • Height: Surface

  • Comments: fish can eat all

35. Myriophyllum, Red Stem - Parrot Feather & Spicatum Milfoil

  • Hardiness:

  • Water depth: 30-60cm

  • Height: stems 20-150cm, leaf 2.5-5cm

  • Comments: Oxygenator. Good around flowing water and pond edge.

37. Nymphoidies Peltala – Water Fringe

  • Hardiness: 5-10

  • Water depth: 30-60 cm

  • Height: surface

  • Comments: Plant in 4ltr pots. Can be vigorous needing regular control.

38. Pistia Stratoides – Water lettuce

  • Hardiness: 10-11

  • Water depth: floating

  • Height: surface

  • Comments: needs warm temperatures best brought in during winter.

Submerged Aquatic Plants:

Floating Plants:

  • Cabomba caroliniana

  • Ceratophyllum Demersum - Coontail / Hornwort.

  • Egeria Densa – Anacharis, can be invasive.

  • Elodea Canadensis – good nutriance remover, can be vigorous.

  • Potamogeton Crispus.

  • Aponogeton Distachyus – Water Hawthorne, zones 6-9 *

  • Azolla Caroliniana – Fairy moss, good compost activator which controls vigorous growth.

  • Eichhornia Crassipes – Water Hyacinth, can be invasive, good water filter.

  • Hydrocharis Morsus-rancea – Frogbit

  • Lugwigia Sedioides – Mosiac Plant

  • Nymphoides Geminata – Yellow fringe.

  • Nymphoides Cristatum – Variegated water snowflake.

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