Magnesium, Salt or Chlorine? The Best Water Selection for Plunge Pools

Choosing your water care system is a quiet decision that shapes comfort, maintenance, and the year round cost for your plunge pool. If you’re weighing magnesium vs salt vs chlorine for a compact Aussie Plunge Pool™ (5,000L to 11,000L), this guide gives you the clear, non-hype truth—how each feels on skin, what you’ll actually need to do each week, and what a year of maintenance may cost for you in Aussie conditions.

We will also show you exactly how simple it is to switch water options later down the track if you wish. And lastly we will finish with a quick “who should choose what” matrix so you can decide with confidence what suits your family best.

1) Skin Feel, Buoyancy & Comfort: What’s Actually True

First, a myth-buster:

• Salt and mineral/magnesium pools are not chlorine-free. They use a chlorinator cell to generate chlorine from dissolved salts (sodium chloride for salt systems, magnesium/potassium chloride blends for “mineral” systems).

• The “pool smell” people dislike isn’t free chlorine—it’s chloramines (combined chlorine) from insufficient oxidation or poor balance. Managed correctly, any of the three systems can smell neutral and feel great.

How each feels

• Chlorine (manual dosing): When balanced (pH/alkalinity/CYA right), water feels clean and neutral. If you’ve ever had “itchy” water, that’s usually pH drift or high chloramines—not the fact it’s chlorine.

• Salt (sodium chloride ~3,000–5,000 ppm): Slightly silkier mouthfeel/skin feel due to higher total dissolved solids. Many owners describe it as “softer” on eyes and hair compared with badly balanced manual chlorine pools.

• Magnesium/mineral (MgCl₂ + KCl blends, usually 3,500–5,500 ppm in total depending on the system): The hero here is bather comfort—some people report silkier water, lighter buoyancy and less post-swim dryness. It’s still chlorinated, but the mineral mix can feel more “spa-like,” especially when paired with a heat pump for evening soaks.

Who notices the difference most?

• People with sensitive skin or those who soak daily tend to prefer salt or mineral for the silkier feel.

• Occasional users (quick cool-offs) often don’t notice huge differences—balancing basics matter more than the label on the bag.

HOT TIP : Because water volume is low, cover discipline and pH control have an outsized impact on how the water feels—whatever system you choose.

2) How Much Maintenance Does Each Water System Need?

Small plunge pools are brilliant because everything responds fast—heat, clarity, comfort. The trade-off is that imbalances also show up sooner. Build a simple, predictable rhythm and you’ll spend minutes per week, not hours.

What stays the same across systems:

• Test weekly (or twice-weekly in heatwaves): Free Chlorine (FC), pH, Total Alkalinity (TA). If using stabiliser (CYA - Cyanuric Acid — also called stabiliser or conditioner), check monthly.

• Brush & skim: a quick once-over keeps surfaces slick and the filter happy.

• Filter run-time: smaller volumes often need shorter, smarter cycles. Use a timer; add a thermal/leaf cover to slash debris and evaporation.

What’s different by system:

• Chlorine (manual): You’re the chlorinator. Dose daily/near-daily in peak summer (or every few days with a dosing pump). You’ll buy liquid chlorine or tablets, plus acid to control pH.

• Salt (SWG chlorinator -Salt Water (Chlorine) Generator—often just called a salt chlorinator.): The cell generates chlorine automatically. You’ll top up salt after backwashing/spills and adjust output seasonally. Clean the cell occasionally (as per manual).

• Magnesium/mineral: Similar to salt, but you’ll replenish mineral blend instead of straight salt. Some systems run at lower TDS (Total Dissolved Solids) than classic salt pools. Expect comparable automation to salt with a different consumable.

Why small pools are easier overall:

• Less volume = faster corrections. If the sun and swimmers chew through FC, a small bump on the chlorinator (or a quick manual dose) resets things quickly.

• Less plumbing = simpler troubleshooting. You’ll learn your pool’s rhythm in a fortnight.

SET-AND-FORGET TIP: A salt or mineral chlorinator with a cover is the lowest-touch combo for most families. Manual chlorine is cheapest upfront but wants more hands during summer.

3) Cost Over 12 Months: Realistic Ranges

Small Pools = Small Bills. And although costs vary by climate, bather load, shade, and how often you heat, for 5,000L to 11,000L plunge pools, these indicative ranges help you compare like-for-like.

Indicative 12-month water care costs for a 5,000L to 11,000L Aussie Plunge Pool™ (October 2026)

Prices checked October 2026: Bunnings (20kg pool salt), Pool Perfect (15L liquid chlorine), Mr Pool Man and My Fibreglass Pool Easy (mineral blends and dosing), Pool Set, Direct Pool Supplies and Mr Pool Man (small-pool chlorinators), My Online Pool Shop (Hydroxinator iQ), What's The Damage? (cell replacement). Costs vary with rain, splash-out, backwashing and how often you heat.

* Pump/filter/heater are separate and similar across systems.

** Chlorinator power draw is modest; heating is the big variable and depends on set-point, cover use, and climate.

Two levers matter more than pump/filter/heater brand:

• Covers cut evaporation (your #1 heat loss) and leaf load—dramatically reducing chemicals and run-time.

• Targeted temperatures (e.g., 26–28 °C evenings) keep comfort high while power bills stay reasonable in small volumes.

Switching Systems Is Easy in Small Pools - Step-by-Step

One of the perks of compact water is flexibility. If you try one path and want to switch, the process is straightforward.

1. Baseline test & record: FC (Free Chlorine) , pH, TA (Total Alkalinity) and CYA (Cyanuric Acid)

2. Decide if you’ll dump/replace some water (to reset TDS- Total Dissolved Solids) or convert in place. Small pools make partial changes affordable.

3. If moving to salt/mineral: add the recommended kg/ppm gradually with the pump running.

4. Install/enable chlorinator (salt or mineral). Set output low and ramp as you learn demand.

5. Re-balance pH/TA, confirm FC is stable, and use your cover.

6. Observe for a week, then fine-tune. Keep notes; small pools “teach” quickly.

Good news: most (but not all) pump/filter/heater stay the same no matter what water type- but please double check this with the manufacturer. The main change is consumable (liquid chlorine vs salt vs mineral blend) and whether you automate chlorination.

Which Water Is Right for You?

Chlorine, salt or magnesium: which suits your plunge pool?

Bottom line:

• Choose Chlorine (manual) if price is critical and you’re happy to dose.

• Choose Salt (SWG -Salt Water (Chlorine) Generator) if you want automation + value.

• Choose Magnesium/Mineral if water feel is your top priority and you’re comfortable with slightly higher consumables.
  

A Note on Aussie Plunge Pools™ - Why Smaller Water Volumes Help Either Way

Because the shells are compact (5,000L to 11,000L), you get:

• Fast heat response (great for shoulder seasons)

• Small chemical bills (less water to treat)

• Easy switching (partial changeovers are affordable)

• All three systems can deliver crystal-clear, comfortable water when balanced; your habits (cover use, weekly test, pH control) do the heavy lifting.
  

Frequently Asked Questions: Magnesium, Salt And Chlorine Plunge Pools

Is a magnesium pool chlorine-free?

No. Magnesium and salt pools both make chlorine through a chlorinator cell. The minerals change how the water feels, not how it's sanitised. You still test free chlorine and pH every week.

What's the cheapest water system for a plunge pool?

Manual chlorine costs the least upfront, because there's no chlorinator to buy. Salt costs more to set up but less each year, at about $60 to $120 in consumables for a 5,000L to 11,000L Aussie Plunge Pool™. It also saves the most effort.

How much salt does a plunge pool need?

At 4,000ppm, you need about 4kg of salt per 1,000L. That's around 20kg for a 5,000L pool and 44kg for the 11,000L Infinity-8, or one to three 20kg bags.

Can I switch from chlorine to salt or magnesium later?

Yes. In a small pool you add the salt or minerals gradually and fit a chlorinator, while the pump and filter usually stay the same. Check that the chlorinator suits mineral water before you buy. Our running costs guide shows what each system adds to your yearly bill.

So, Which Water Will You Choose?

Forget the hype: all three systems use chlorine—they just deliver it differently. In small plunge pools, the biggest comfort wins come from balance, covers, and consistent routine. Pick the path that fits your budget and lifestyle now. And remember: you can change your mind later—small water volumes make it simple.