What this actually is
A Swimming Lagoon at Biosphere is two things at once.
It's a lagoon - the shape of a tropical shore set into your property. White sand running into the water at one end. Shallow zones to stand and sit in. A deeper centre for actual swimming. Rocks set the way they sit on a real shore.
And it's a working ecosystem - clear enough to snorkel in, and stocked with colourful fish that live there year-round. Koi, ghost koi, and smaller ornamental species chosen for the way they look against white sand and clear water.
You won't find this in a chlorinated pool - fish don't survive chlorine. You won't find it in a salt pool - fish don't survive salt. You find it in places where the water is alive and held that way by biology, not chemistry. We build that, at the scale and shape of a lagoon, on private property.
What it feels like
Walk in from the sand entry, knee deep, then thigh deep. Put a mask on. The floor is white sand and set stone. The light is doing what light does through clear shallow water. There are fish, and they're not subtle about it - colour is the whole point.
This is the closest thing to snorkelling in a coral lagoon that exists outside a coral lagoon. It's quieter. The setting is your own land. But the experience - water you can see through, colour moving around you, the half-buoyant feeling of being in shallow tropical water - is the same.
Most clients who build one of these say the same thing after the first season: they expected a beautiful pool and they got an entirely different kind of property.
What sits underneath
Holding water this clear, this shallow, with this much sun on it, with a fish population living in it, is the hard part.
The lagoon look is the easy part. A standard biological pool runs on a planted regeneration zone - aquatic plants doing the filtration work in a shallow shelf alongside the swim area. That works for a Bio Swim Pond. It doesn't carry the load of a lagoon with a healthy fish population swimming through it.
The lagoon system is built differently. Three things work together to hold the water:
A multi-stage biological filtration train - mechanical pre-filtration followed by a high-rate biological reactor sized for the fish load, rather than for a planted shelf.
PhosPure™, our in-house phosphate control system. Phosphate is the food algae lives on. Most clear-water failures in fish-bearing systems come down to phosphate creeping up over time, the algae following, and the clarity dropping. PhosPure™ removes phosphate continuously and quietly, before it ever has the chance to feed anything.
ECO-O3, our in-line ozone polishing system, engineered specifically for the chemistry and the climate of Indian sites. Ozone is a powerful oxidiser that takes the water beyond what biological filtration alone delivers. It's what holds the clarity at the level snorkelling needs.
There's still planting around and into the lagoon, because the planting is part of how the form reads. But it isn't doing the filtration work. The engineering is.
Pumps are German. The sand is selected for whiteness, grain, and the way it stays put without clouding the water. The boulder work is set, not faced.
You don't see most of this when you're in it. That's the point.
What you can expect
-
Water you walk into rather than climb into - a sand-shore entry that slopes the way a beach does.
-
Shallow zones to sit and lounge in, knee or thigh deep, with chairs that live in the water.
-
A deeper centre to actually swim and snorkel in.
-
A live population of colourful ornamental fish - koi, ghost koi, and smaller species - chosen for the site, the planting, and how you want the water to read.
-
Shoreline and edge planting that changes through the seasons and frames the lagoon from every angle.
-
Underwater lighting designed in from the start.
-
No chlorine, no salt, no daily chemistry. The biology, PhosPure™, and ECO-O3 do the work.
-
Shoreline and edge planting that changes through the seasons and frames the lagoon from every angle.
-
Underwater lighting designed in from the start.
-
No chlorine, no salt, no daily chemistry. The biology, PhosPure™, and ECO-O3 do the work.
What it asks of you
This page wouldn't be honest if it only listed what the lagoon gives you. Holding a fish-bearing lagoon at this clarity asks something back.
The maintenance is real. The fish need feeding and observing. The filtration system, while it doesn't need chemical dosing, does need monitoring and seasonal servicing. The planting around the lagoon needs tending the way any considered garden does. Most clients don't do this themselves - we provide an annual maintenance contract for exactly this reason, and most of our lagoon clients are on one.
The seasons show on the water. The lagoon in April reads differently from the lagoon in August. That's part of what makes it a living thing rather than a pool. If you want water that looks the same every day of the year, this isn't the right product.
The fish are an ongoing relationship. Not a one-time stocking. They breed, they age, some are lost, new ones are added. They become part of the property the same way a garden does.
We mention all of this up front because the wrong client for this build will struggle with what we've just described, and the right client will read it and recognise themselves.
Where a Swimming Lagoon belongs
A weekend estate where the property is built around being outside. A villa with land to spare and a brief that won't be met by a rectangular pool. A boutique resort where the water is the photograph the property is known for. A wellness retreat where the swim is part of the treatment, not a facility on the floor plan.
These projects share a quality of brief - the owner isn't asking for a pool with extras, they're asking for somewhere to be. The lagoon is the answer to that brief.
It's a larger commitment than either of our other swim forms. More land, more water volume, more shoreline, a more advanced filtration system, and a living population of fish that becomes part of the property. The price reflects that, and so does the result.
How a Swimming Lagoon comes together
1
Project Assessment
We walk the site, listen to the brief, and test it against what the engineering needs - orientation to the sun, slope, soil, water table, the path the water actually wants to take. The lagoon form is more site-sensitive than the others; the assessment matters more here. Paid preliminary stage. If we proceed, the fee credits to the project.
2
Design
The shape of the shoreline, the sand-entry, the depth gradient, the rockwork, the cascades, the way the lighting reads at night, and the filtration train - biological, PhosPure™, ECO-O3 - sized to the fish population the lagoon will hold. Drawings you can build from.
3
Construction
Excavation, profiling, liner, hydraulics, biological filtration build, PhosPure™ install, ECO-O3 install, rockwork, sand placement, planting. The build is longer than for a pool of equivalent value because the form is doing more work.
4
Establishment
The system takes a few weeks to balance, and the lagoon takes a season to settle into its final clarity. The fish are introduced in stages through that period. We stay on through establishment and hand over with a clear plan, an annual maintenance contract, and a relationship that continues from there.
A note on what we don't do
We build new. We don't retrofit existing pools into lagoons, and we don't take on conversions of ponds that weren't engineered for swimming.
The lagoon form is unforgiving of shortcuts. The shoreline gradient, the sand-water interface, the filtration sizing, the fish-loading calculation - these can't be patched in afterwards. Better not to start.
Often part of something larger
A lagoon rarely arrives alone on the sites it suits. A stream feeding it from a higher level. A cascade in the rockwork. A koi pond near the house with the lagoon further out in the landscape. A planted lake at the far edge of the property, with the lagoon as the place you actually swim.
Every element can be designed and engineered as one continuous system
A swimmable body of water designed to look and feel like a tropical shore - white sand base, shallow lounge zones, a deeper swim area, set rockwork and shoreline planting, and a live population of colourful ornamental fish. The water is filtered biologically, phosphate-controlled by our PhosPure™ system, and polished by our in-line ozone system, ECO-O3.
Yes. The water clarity is held by a multi-stage biological filtration train, PhosPure™ phosphate control, and ECO-O3 ozone polishing. The fish live in the lagoon year-round at densities chosen to suit both the ecosystem and the experience. Most clients spend more time in the lagoon than they expected to.
Most African cichlids and Japanese koi, with smaller ornamental species added where the brief calls for it. They're selected for colour, for how they read against the white sand floor, and for how they live in the planting palette. The final selection is part of the design conversation.
ECO-O3 is our in-house in-line ozone system, designed specifically for Indian site conditions - heat, monsoon load, and the chemistry of local water supply. Ozone is a powerful oxidiser that polishes the water beyond what biological filtration alone achieves. It's part of what makes the snorkelling clarity possible. We use it on lagoons and on the larger end of our other builds where the load demands it.
PhosPure™ is our in-house phosphate control system. Algae feeds on phosphate, and phosphate accumulates in any active water body - from fish waste, from organic matter, from the water source itself. Most clear-water failures in fish-bearing systems come down to phosphate creeping up unnoticed. PhosPure™ removes it continuously, so the conditions algae needs to bloom never arrive. It's part of why the snorkelling clarity holds across the year, not just the first season
A Bio Swim Pond carries a much lower fish load relative to its planted area, and the regeneration zone handles the phosphate load that does build up. A Swimming Lagoon - denser fish population, no planted regeneration zone doing the work, much more sun on shallow water - produces phosphate at a rate biological filtration alone can't keep up with. PhosPure™ is the answer to that specific problem.
A Bio Swim Pond is filtered by a planted regeneration zone - aquatic plants doing the work in a shallow shelf alongside the swim area. That works beautifully for the pond form and the loads it carries. A Swimming Lagoon, especially one with a fish population swimming through it, needs more than a regeneration zone can deliver. The filtration here is a multi-stage engineered system, with PhosPure™ handling phosphate control and ECO-O3 doing the final polish.
Both are natural, both are chemical-free, both can hold fish. They read very differently. A Bio Swim Pond is a pond - stone edges, planted margins, the feel of a natural water body in the landscape. A Swimming Lagoon is a coastline - sand entry, shallow blue water, the feel of a tropical shore, and a denser fish population stocked for the snorkelling experience. The filtration systems are also different - see the question above.
More than a chlorinated pool of comparable size, less than people expect once they see how the system runs. The fish need daily feeding and weekly observation. The filtration system needs monitoring and seasonal servicing. The planting around the lagoon needs tending as any considered garden does. We provide an annual maintenance contract that covers all of this, and most of our lagoon clients are on it.
No. The build price starts at Rs 80 Lakhs. The annual maintenance contract is separate and quoted to the specific lagoon - based on size, fish load, filtration scope, and the site. We share the figure during the Project Assessment so you can plan around it.
More than a pool, less than a lake. The form needs room to gradient - the sand entry, the shallow zones, the deeper centre - and it needs sun. We'll know after a site visit whether the land you have can hold one well.
Swimming Lagoons start at Rs 80 Lakhs. Where a specific project lands depends on size, the volume of sand and rock, the planting, the cascades, the lighting, the fish population, and what the site itself demands. You'll have a firm number after the Project Assessment, not before.
Yes, with seasonal care. The sand is selected for grain and density so it sits where it's placed instead of drifting. Like any beach, it benefits from being raked occasionally. The maintenance contract covers it.
Yes. Ours are engineered specifically for local conditions - high ambient temperature, monsoon load, evaporation, sun load on shallow water, and the fish populations that thrive here. PhosPure™, ECO-O3, and the rest of the filtration train are sized for the climate the lagoon is built in.
The opposite. Mosquitoes need still water, and a Swimming Lagoon is continuously moving and oxygenated. The fish eat any larvae that do appear. Dragonflies and other natural predators tend to find the ecosystem on their own.
Typically two to four months from design sign-off to handover, depending on size, site access, and the scope of shoreline and rockwork. The system then balances over a few weeks, and the lagoon settles to its full clarity over the first season. Fish are introduced in stages through that period.
No. We build new only. The shoreline gradient, the sand interface, the filtration sizing, the fish-loading calculation - none of these can be retrofitted onto an existing pool shell.
Common questions about Swimming Lagoons
Looking at more than one option? See how our Bio Swimming Pond, Bio Swim Pool, and Swimming Lagoon compare.
