Natural Swimming Pools Ltd. have been building and maintaining natural swimming pools since 2001. Before that we built up a wealth of experience as landscape gardeners, transforming outdoor spaces and building stunning water features. We now work all over the UK and overseas and our pools regularly feature on TV and in lifestyle magazines.

We operate from an office in East Anglia but cover the entire UK and have also completed projects in mainland Europe.

Our team consists of skilled builders, landscapers and plant specialists. We can provide a complete planning, construction and aftercare service and can tailor every aspect of the design to your personal preferences. We’ve been doing this for so long that there isn’t any request we can’t handle!


Natural pools not only add atmosphere and value to a property, they don’t have to cost as much as you think. We guarantee pools of exceptional quality at a reasonable price. 

  • The base cost for natural filtration is a swimming pool converter system that starts at around £20,000 +VAT. Conversions with plants start at £45,000 +VAT.
  • Pools with plants start at £55,000 +VAT.
  • Small pools without plants start at £50,000 +VAT.

A converter changes a swimming pool from chemical to natural biologically filtered water.

Concrete block walls are used most frequently, but other more environmentally-friendly options are available.

Curved walls and edges take the most time to build.

Least costly earth wall construction (subject to ground conditions and pool design).

Biotop modular unit walls are made from recycled plastic and cut time and cost.

Section of pool with plant filter, skimmer, pump and phostech filter.


Underwater scythe for water lilies

Swimming area robot

Pool Hoover

Skimmers clear surface debris to 0.3mm

Pools with Plants

Maintenance is simple, easy and enjoyable in such a natural setting . The surface skimmer needs emptying regularly – the frequency depends on the season. The plants should be pruned (although not essential) in the summer to help filtration, then fully cut back in the autumn. The swimming area is cleaned with an automatic robot regularly or a hand-held vacuum occasionally for lazier ‘swimming ponders’.

At 3 to 5 year intervals, a full service is needed to rejuvenate plant growth and eliminate anaerobic silt that builds up. This is about 2 to 3 days hard work which we will do for you if needed. Our pools are unique as the  special profile design means this is easily done with part-emptying only.  This adds to the construction cost but generates significant savings in time and maintenance costs over the years. The plant filtration system can be switched off separately but  water features and leaf clearing left on in the winter.

Pools without Plants

Maintenance is very simple, with nature doing the hard work.  It is less than an ordinary swimming pool as no regular testing and chemical dosing is needed. Skimmers are emptied occasionally.  The filtration is a living biological filter which breaks down waste without adding anything. A natural phosphate absorbing material is replaced by us at 2 to 3 year intervals. This filter needs back flushing and stirring occasionally to maintain even flow.

A robot cleans the surfaces on a daily cycle and can be left in the pool when not swimming. Pool steps, awkward corners and slopes or sides may need brushing to prevent them getting too slippery or discoloured by biofilm. The biological pool filtration can be switched off in winter but leaving the skimmer pump on helps to keep the pool cleaner.

We do all seasonal maintenance work for those who don’t wish to do it themselves. We offer complete support, fast response and remedies for any running issues that may occur.

Each pool comes with a comprehensive handbook on maintenance.


The costs for natural pools maintenence vary depending on the pool type size and method. The lowest cost is to Do-it-Yourself (very easy). Plant feed is  £25 – £100 per season. Tap water is filtered for all pools. Replacement phosphate media will need replacing every 2-7 years approx.  We will confirm costs for this based on style/size of pool.

The pumps are low-power consumption. 

We recommend boreholes as the best method of filling all pools. Their costs can offset filtering costs and water rates within 5 to 10 years. The water is higher quality and plant growth is better.

Pools without plants need less work but have higher running costs. Phosphate media that replaces plants (which grow for free) must be replaced when saturated. Replacement is done every 2-3 years. Costs also vary with environmental conditions, such as location, weather and level of use and care.  We will confirm costs dependent on pool size.


Pools can be made warmer than you think in several ways:

Option 1 – Sunshine

Natural swimming pools with 50% or more shallow planting warm from the sun, hold heat well and sit at around 21C to 25C in summer. They will often reach daily maximum air temperatures by the afternoon.  Heating improves by increasing the shallow area; we can extend shallow areas significantly or even put in underground heat collection pipes.

Option 2 – Covering

Covering is the most cost-effective means of increasing pool temperature. Floating solar panel covers will significantly raise temperatures above air temperatures if sunny. Dark liners also attract the sun’s radiation.  Covers can be fitted to all types of pool except over the planted areas. This is much the best way for warmer swimming without high running costs. Solar covers cost £15 – £25,000. Hand reel-out bubble covers are about £2,500 as a budget option.

Option 3 – Heat pumps

Heating natural water is absolutely fine up to 28C. Pools are most efficiently heated by an air source heat pump. The swimming  area  should be covered to make it viable. Costs are between  £6 – £15,000 for airsource heaters depending on season required.