Inground Pool Saltwater Conversion Cost by Pool Size

You’ve heard saltwater pools are easier to maintain, gentler on skin, and cheaper to run over time – and now you’re wondering what it actually costs to make the switch on your inground pool. The problem is every number you find online seems to be a different ballpark, and nobody breaks it down by pool size.

The short answer: converting an inground pool from chlorine to saltwater costs between $1,200 and $3,500 for most homeowners, with the main variable being pool size and whether you hire a pro or do it yourself. The conversion itself is not complicated – it comes down to buying a salt chlorine generator sized to your pool, having it installed, and dissolving the right amount of pool-grade salt into the water. This article breaks down the cost by pool size, explains what’s included in that price, flags the hidden expenses people miss, and covers what changes about day-to-day maintenance afterward.

What You’re Actually Paying For

A saltwater pool is not a chlorine-free pool – that’s the most common misconception worth clearing up immediately. A salt chlorine generator (also called an SWG or salt cell) uses electrolysis to convert dissolved salt into chlorine continuously, so your pool is still sanitized by chlorine, just produced on-site rather than bought in bags or tabs. The conversion cost covers four things:

• Salt Chlorine Generator: The control unit and electrolytic cell, which mounts inline on your return plumbing after the heater or filter. This is the biggest single cost, ranging from $600 for a basic 15,000-gallon unit to $2,000+ for a large-pool, variable-output model.
• Installation Labor: A pool tech typically charges $300-$600 to cut the return line, glue in the cell housing, wire the control box, and set the initial parameters. Electrical work adds cost if your equipment pad needs a new circuit.
• Pool-Grade Salt: You need to raise the water’s salinity to roughly 3,000-3,200 ppm. The cost depends entirely on pool volume – more on that below.
• Chemistry Adjustments: Cyanuric acid (stabilizer) needs to be at 70-80 ppm in a saltwater pool to protect the generated chlorine from UV breakdown. If yours is low, budget $20-$50 for stabilizer. Keep in mind that phosphates in your pool water can undermine sanitizer efficiency regardless of whether you’re running a salt system or traditional chlorine, so test for those too before you start.

Cost by Pool Size: Real Numbers

Pool size determines two costs: the generator capacity you need and the pounds of salt required for the initial fill. The table below covers the most common inground pool sizes. Salt prices are based on 40 lb bags at $5-$8 each, and generator prices reflect mid-grade units that most pool owners actually buy (not the cheapest no-name cell, not the top-of-the-line variable unit).

Pool Size (approx. gallons)	Salt Needed (lbs)	Salt Cost	Generator Cost (mid-grade)	Labor (pro install)	Total Estimated Range
10,000 gal (12×24)	250-300 lbs	$32-$60	$600-$900	$300-$500	$932-$1,460
15,000 gal (14×28)	375-450 lbs	$47-$90	$700-$1,100	$300-$550	$1,047-$1,740
20,000 gal (16×32)	500-600 lbs	$62-$120	$900-$1,400	$300-$600	$1,262-$2,120
25,000 gal (18×36)	625-750 lbs	$78-$150	$1,100-$1,600	$350-$650	$1,528-$2,400
35,000 gal (20×40)	875-1,050 lbs	$110-$210	$1,400-$2,000	$400-$700	$1,910-$2,910

Why These Numbers Can Shift Significantly

The table above assumes your existing equipment is compatible and your plumbing is straightforward. Several factors push the real cost higher:

• Incompatible Heater: Salt systems require a titanium or salt-compatible heat exchanger. Many older heaters have copper components that salt water corrodes. Replacing a heater adds $1,200-$3,000 to the project.
• No Suitable Electrical Circuit: Most salt generators need a dedicated 110V or 240V circuit at the equipment pad. If your panel doesn’t have room or the run is long, electrician costs of $200-$500 are realistic.
• Bonding and Grounding: The salt cell must be bonded to your pool’s existing bonding grid. Inspectors in some states require this to be verified or upgraded, adding $100-$300.
• Low Calcium Hardness: If your calcium hardness is below 200 ppm (common in pools that used trichlor tabs for years), you’ll need to add calcium chloride before running the system, or the slightly aggressive saltwater will start eating at your plaster. Budget $30-$80 for the initial dose.

As River Pools and Spas explains in their saltwater conversion guide, buyers who don’t account for heater compatibility are often the ones whose conversion costs double unexpectedly. It’s worth checking your heater’s manual before you buy the generator.

DIY vs. Professional Installation

Doing the conversion yourself saves the $300-$650 labor line. The mechanical work – cutting the PVC return line, gluing in the cell union fittings, mounting the control box – is well within reach if you’ve done any plumbing before. The part most people hire out is the electrical connection. Running a new circuit or adding a GFCI outlet at the equipment pad requires a licensed electrician in most jurisdictions, and pool equipment near water is not the place to improvise.

A realistic DIY cost for a 20,000-gallon pool: $900-$1,400 for the generator, $62-$120 for salt, $50-$80 for any chemistry adjustments, and $150-$250 if you hire an electrician just for the wiring. Total: roughly $1,162-$1,850 – compared to $1,262-$2,120 with a full pro install. The savings are real but not huge, so the decision mostly comes down to your comfort level with the plumbing and electrical work. Schiller Pools has a useful overview of what the inground conversion process involves if you want to walk through the steps before committing.

What Changes About Ongoing Maintenance (and What Doesn’t)

After conversion, you stop buying chlorine tabs or granular chlorine for routine use – that’s the main ongoing saving. The generator handles sanitization automatically. You still test the water 2-3 times per week and still manage pH, alkalinity, calcium hardness, and cyanuric acid the same as before. Salt pools actually tend to push pH upward over time (the electrolysis process releases hydrogen gas and raises pH as a byproduct), so you’ll use more pH reducer than you did before.

The generator cell itself needs cleaning every 3-6 months: a brief soak in a diluted acid solution to remove calcium scale from the plates. Most units have a self-cleaning cycle, but in hard-water areas you’ll still need to inspect and manually clean occasionally. Cell replacement is the main ongoing capital cost – plan on $200-$500 for a replacement cell every 3-7 years depending on how hard you run it and your water chemistry discipline. AquaDoc’s pool salt is one option pool owners use at startup and when topping off after heavy rain or splash-out, since high-purity salt keeps the cell cleaner over time.

For day-to-day water clarity, the chemistry principles don’t change. If you run into cloudy water after conversion – often triggered by the chemistry shift during startup – the troubleshooting process is the same as with any pool. Our guide on cloudy pool water causes and fixes covers the most likely culprits and how to correct them without draining.

One thing worth knowing: cyanuric acid (stabilizer) does not get consumed by the salt system. Once you set it at 70-80 ppm, it stays there until you dilute the pool with fresh water. If your level was already high from years of stabilized trichlor tabs – 100 ppm or above – you may need a partial drain before converting, or your generated chlorine will be effectively locked up and unable to sanitize. Check the pool stabilizer guide if you’re unsure where your CYA level stands.

Is the Conversion Actually Worth It Financially?

At current prices, a 20,000-gallon pool using traditional chlorine tabs costs roughly $400-$700 per season in chlorine alone. A saltwater pool running the same volume costs about $50-$100 in salt top-offs per season (you only replace what splashes out or evaporates), plus electricity to run the generator (typically $30-$60 per season on a variable-speed pump setup). That’s a savings of $300-$600 per year after conversion. At a total conversion cost of $1,262-$2,120, payback takes roughly 3-5 seasons. Del Rancho Pools walks through a similar cost-benefit comparison if you want a second set of numbers to compare against your own situation.

The case for converting is stronger if you’re also motivated by the water feel (saltwater pools feel noticeably softer and less harsh on eyes and skin) or the reduction in handling concentrated chlorine products. Those are real benefits that don’t show up in a spreadsheet but matter to a lot of pool owners.

Frequently Asked Questions

How much does it cost to convert a 20,000-gallon inground pool to saltwater?

A 20,000-gallon inground pool typically costs $1,262 to $2,120 to convert, including a mid-grade salt chlorine generator ($900-$1,400), professional installation labor ($300-$600), and the initial salt charge of 500-600 lbs. DIY installation on the plumbing side saves $300-$500, though most people still hire an electrician for the wiring.

Can I convert my inground pool to saltwater myself?

Yes, and many pool owners do. The plumbing work – cutting the return line and gluing in cell fittings – is manageable if you have basic PVC skills. Hire a licensed electrician for the control unit wiring and any new circuit work at the equipment pad. Total DIY savings are typically $300-$600 compared to full professional installation.

What size salt chlorine generator do I need for my pool?

Buy a generator rated for at least your pool’s actual volume, but ideally one rated 25-30% larger. A 20,000-gallon pool runs better with a generator rated for 25,000-30,000 gallons because operating the cell at 60-70% output instead of full capacity significantly extends cell life. Most cells are rated for 10,000 hours, and running them at 100% burns through that rating in 3-4 seasons instead of 5-7.

How much salt do you need to start a 30,000-gallon saltwater pool?

A 30,000-gallon pool needs approximately 750-900 lbs of pool-grade salt to reach 3,000-3,200 ppm salinity – about 19-23 bags of 40 lb salt, costing $95-$185 depending on your area. Add the salt directly to the pool, brush it toward the main drain, and run the pump for 24 hours before turning the generator on. This lets the salt fully dissolve before the cell starts doing its job.

Does converting to saltwater damage a plaster or fiberglass inground pool?

Saltwater at the correct concentration (2,700-3,400 ppm) does not damage plaster or fiberglass when calcium hardness is kept between 200-400 ppm. The risk is low calcium hardness – below 200 ppm, even mildly aggressive water will leach calcium from plaster surfaces over time. Test calcium hardness before you convert and correct it if needed; this is the single most common maintenance mistake new saltwater pool owners make.

For most inground pools, the saltwater conversion pays for itself in 3-5 seasons through reduced chlorine costs, and the lower-maintenance, softer-water experience makes the upfront investment hard to argue against once you’ve run the numbers for your specific pool size.