Pool to Pond Conversion
Turn the chlorine pool you already own into a natural swimming pond. Same footprint, no chemicals, water kept clear by plants and gravel biology. Most conversions cost $140,000 to $320,000 within our $120,000 to $750,000 range and take six to twelve weeks of construction.
Published · By Craig McBride
How the conversion works
The existing shell becomes the deep swim basin. We drain the pool, strip coping and failing plaster, cut a shallow planted regeneration zone alongside or inside the footprint, re-line the whole basin as one waterproof body of water, repipe circulation through a biological filter instead of the chlorinator, then plant, fill and commission.
What it costs
Conversions sit inside the same range as new builds: $120,000 to $750,000, with most projects between $140,000 and $320,000. Reusing the shell and original excavation saves real money, but liner, regeneration zone, repiping, stone and planting are all new work.
How long it takes
Six to twelve weeks of construction for most residential conversions, plus permitting where required. The pond is swimmable at commissioning, and the planted zone needs one growing season to reach full filtering strength, a spring start swims well by mid-summer.
The shell and the plumbing
A sound gunite or concrete shell is kept, not demolished. Skimmers and returns are commonly reused after repiping. Chlorinators, salt cells and pool-sized heaters are usually removed, and pumps stay only where the flow rate suits a low-pressure biological loop.
Which pools convert well
Good candidates: sound gunite or concrete shells, at least six feet of depth somewhere in the basin, and usable yard alongside for the planted zone. Poor candidates: very small pools with nowhere for a regeneration zone, shells with unresolved structural movement, and sites where equipment cannot reach.
Regeneration zone area
The planted zone replaces chlorine, so its area is the critical design decision. We target roughly as much shallow planted surface as swim surface, about half the finished water. Where the yard cannot give that up, engineered gravel filtration and stronger circulation make up the shortfall.
Your first season
Water clears over the first four weeks as bacteria colonise the gravel, a light algae bloom is normal while plants are small, and by the end of season one the biology carries the load. Annual deep cleaning of the filters starts at $2,500.
Overview
Turn the chlorine pool you already own into a natural swimming pond. Same footprint, no chemicals, water kept clear by plants and gravel biology. Craig McBride has been building natural ponds for 31+ years, with 50+ completed projects across five states.
The conversion process, step by step
Site and shell assessment. We inspect the shell for structural cracking, check the depth profile, measure the surrounding yard for regeneration zone space, and locate the existing plumbing and electrical runs. Design. We lay out the swim zone, the shallow planted zone and the edge treatment, and size the circulation so the whole volume turns over through biology rather than chemistry. Drain and demolition. The pool is drained, coping and any tile or plaster that will not work under a liner comes off, and the chemical equipment is disconnected. Regeneration zone excavation. New shallow shelves are cut, either inside the existing footprint or extending into the yard beside it. Liner and stone. Underlayment and liner go over the shell and the new zone as one continuous waterproof basin, then boulders, gravel beach and edging hide every liner edge. Plumbing and circulation. Water is repiped from the old chlorinator loop into the biological filter and back through the planted zone. Planting and fill. Native aquatic plants are set into gravel beds and the pond is filled and dosed with beneficial bacteria. Commissioning and training. We hold the water through its first clearing cycle, test it, and teach you the routine. Our 12-month workmanship warranty covers plumbing and hardware and the water-clarity guarantee 30 days.
What it costs and what drives the number
Conversions sit inside the same range as new builds: $120,000 to $750,000, with most projects landing between $140,000 and $320,000. Reusing the shell and the original dig removes a real slice of the excavation bill, but the liner, regeneration zone, repiping, stone and planting are all new work. A conversion is a rebuild of the water, not a retrofit kit. Pool size and how much new shallow zone has to be excavated beside it Condition of the shell and how much demolition the coping and plaster need How much stone and gravel beach the edge treatment calls for Access for equipment: tight side yards raise labour cost Optional waterfall, stream, lighting or dock work For the full line-item breakdown, read the pool to pond conversion cost guide . For the service itself, including maintenance handover, see our pool conversion service .
How long a conversion takes
Plan on six to twelve weeks of construction for most residential conversions, plus permitting time where your municipality requires a new review. Biology runs on its own clock afterwards: the pond is swimmable as soon as it is commissioned, but the planted zone needs one full growing season to reach full filtering strength. Starting in late winter or early spring gives you a mature-looking, fully biologically active pond by mid-summer.
The shell stays
A sound gunite or concrete shell becomes the deep swim basin. It is not demolished or filled. Coping, tile and failing plaster come off so the liner can sit on a clean surface, and any cracking is repaired before the liner goes down.
The plumbing is repurposed
Skimmers and returns are commonly reused after repiping. Chlorinators, salt cells and pool-sized heaters usually come out. Pumps stay only where the flow rate suits a biological loop, which runs longer hours at lower pressure than pool filtration.
Good candidates
• Gunite or concrete shells in sound structural condition • Pools with usable yard alongside for the planted zone • Depth of roughly 6 feet or more somewhere in the basin • Owners tired of chemical cost and chemical feel • Older pools already facing a resurfacing bill
Poor candidates
• Very small pools with no adjacent space for a regeneration zone • Shells with unresolved structural failure or movement • Sites in permanent deep shade with heavy leaf load and no plan for it • Yards where equipment truly cannot reach the excavation area • Owners who want a hard-edged, chemically sterile pool look We tell people plainly when a conversion is the wrong call. Sometimes the honest answer is a new natural swimming pond elsewhere in the yard, with the old pool decommissioned separately.
How much regeneration zone a converted pool needs
The planted regeneration zone is what replaces chlorine, so its area is the single most important design decision in a conversion. As a working rule we target roughly the same surface area of shallow planted zone as swim zone. Think of it as needing about half the finished water surface as biology. Where the yard cannot give that up, the shortfall is made up with engineered gravel filtration and stronger circulation, which raises equipment cost and running hours. Shallow shelves, typically under 18 inches, planted into gravel beds Placed alongside the pool, or built inside the shallow end where the yard is tight Fed by the same circulation loop as the swim zone, running continuously Separated from the swim area by a submerged wall so gravel stays put See how the zone itself is engineered in our regeneration zone design guide .
Your first season after conversion
Weeks 1-4. Water clears as bacteria colonise the gravel. Expect some cloudiness early on. This is the window our 30-day clarity guarantee covers. Weeks 4-10. A light algae bloom is normal while plants are still small and competing for nutrients. It passes as roots fill the gravel beds. Months 3-6. Plants establish, water settles into a stable clarity, and dragonflies and frogs usually arrive on their own. End of season one. The pond looks planted rather than new and the biology is carrying the load. Annual deep cleaning of the filters starts at $2,500. What that upkeep actually involves is set out on our natural pool maintenance page .
Find out whether your pool is a good candidate
Send us your pool's size and age and we will tell you honestly what a conversion would take.
Frequently Asked Questions
How does a pool to pond conversion work?
We drain the pool, keep the existing shell as the deep swim basin, cut in a shallow planted regeneration zone, re-line the whole basin, repipe circulation through the biological filter instead of the chlorinator, then plant and commission the water.
How much does it cost to convert a pool into a natural pond?
Conversions fall inside our normal build range of $120,000 to $750,000, with most projects between $140,000 and $320,000. Using the existing shell and excavation saves money against a new build.
How long does a pool conversion take?
Most conversions run six to twelve weeks of construction depending on size, permitting and new excavation. Plants then need one growing season to reach full filtering capacity.
Can any pool be converted to a natural pond?
Most gunite and concrete pools convert well. Pools under about 300 square feet rarely have room for a workable regeneration zone, and shells with unresolved structural failure are poor candidates.
Do I still need chlorine after converting?
No. A converted pond is kept clear by plants, gravel biology and beneficial bacteria. Annual deep cleaning of the filters starts at $2,500. A chlorine pool costs $2,000 to $4,000 to run.