A magnesium pool is a swimming pool that uses a blend of magnesium chloride, potassium chloride, and sodium chloride instead of plain salt or traditional chlorine to sanitize the water. The mineral blend passes through a specialized chlorinator (sometimes called a “hydroxinator”) that converts it into chlorine for disinfection, just like a saltwater pool. The difference is in the minerals dissolved in the water and how they affect the swimming experience: the water feels noticeably silkier, is gentler on skin and eyes, and leaves less of the dry, tight feeling you get from a conventional chlorine or saltwater pool.
How a Magnesium Pool Works
The system operates on the same basic principle as a saltwater pool. You dissolve mineral salts into the pool water, and a cell inside the chlorinator uses electrolysis to break those salts down and generate chlorine. The chlorine then sanitizes the water just as it would in any other pool. What changes is the composition of the dissolved minerals. A standard saltwater pool runs on sodium chloride (table salt) at roughly 2,500 to 8,000 parts per million. A magnesium pool uses a proprietary mineral blend where magnesium chloride and potassium chloride replace a significant portion of that sodium chloride.
You still have chlorine in the water. This is a common misconception. A magnesium pool is not chlorine-free. It simply generates chlorine from a different mineral source, and the magnesium left dissolved in the water is what changes the feel and potential benefits of swimming.
What Swimming in One Feels Like
The most immediate difference people notice is the texture of the water. Magnesium-rich water has a soft, smooth quality that’s often compared to bathing in mineral springs. After swimming, your skin tends to feel moisturized rather than stripped, and your hair doesn’t develop the straw-like brittleness that comes with heavy chlorine exposure. Eye irritation is also significantly reduced for most swimmers.
Many pool owners report that the water feels less “chemical” overall. The typical pool smell, which actually comes from chloramines (chlorine reacting with sweat, oils, and urine), tends to be milder in mineral pools because the system often produces fewer chloramines at balanced levels.
Skin Benefits and the Magnesium Absorption Question
Magnesium pools are frequently marketed as a way to absorb magnesium through your skin while you swim, potentially easing muscle soreness, improving sleep, and reducing stress. The science on this is thin. A 2017 review published in PubMed Central evaluated the existing literature on transdermal magnesium and concluded that “the propagation of transdermal magnesium is scientifically unsupported.” The few studies that claimed meaningful absorption through skin lacked full publication or robust data.
That said, there is real evidence that mineral-rich water benefits the skin itself, even if minerals aren’t crossing into your bloodstream in meaningful amounts. Bathing studies using Dead Sea minerals, which are high in magnesium, showed reduced skin inflammation and improved skin barrier function after six weeks compared to plain tap water. The National Psoriasis Foundation notes that swimming in mineral-rich salt water can help remove dead skin and improve psoriasis symptoms. Children with eczema in one trial saw reduced disease severity after bathing in mineral water. So while you may not be “supplementing” magnesium through your pool, your skin can still benefit from the mineral contact, particularly if you deal with dryness, eczema, or other inflammatory skin conditions.
Water Clarity and Filtration
Magnesium has natural flocculant properties, meaning it binds with fine particles of dirt and debris suspended in the water. This clumping effect makes it easier for your filtration system to capture impurities that would otherwise pass through the filter. The practical result is water that looks clearer and requires fewer additional clarifying chemicals. Pool owners often describe the water as having a distinctive crystal-clear appearance compared to standard salt or chlorine setups.
Maintenance and Common Issues
Day-to-day maintenance is similar to a saltwater pool: you test and balance your water chemistry regularly, clean the filter, and occasionally add more mineral salts as they’re consumed by the chlorinator. The key difference is that you’re buying bags of magnesium mineral blend instead of plain pool salt, and the chlorinator cell is designed specifically for that blend.
The most common maintenance issue unique to magnesium pools is mineral scaling. White calcium and magnesium deposits can form on pool surfaces, tile lines, and the chlorinator cell itself if water chemistry drifts out of range. Keeping total hardness below 800 ppm (with calcium hardness ideally under 200 ppm) and maintaining pH right around 7.4 are the main defenses against scaling. If pH creeps above that level, mineral deposits can appear quickly. Pool owners who stay on top of testing rarely have problems, but those who let the water go untested for weeks often find scale building up on surfaces and equipment.
Cost Compared to Salt and Chlorine Pools
Converting an existing pool to a magnesium system requires a compatible chlorinator or hydroxinator, which is the main upfront cost. The unit needs to be rated for the magnesium mineral blend, as standard salt chlorinators aren’t designed for it. Some brands offer conversion kits for existing saltwater systems, while others require a full replacement.
Ongoing mineral costs run higher than plain pool salt. One pool owner in North Queensland reported spending about $1,200 AUD for an entire swimming season (roughly October through April), covering 14 bags of minerals plus supplementary chemicals and testing supplies. Plain salt for a comparable saltwater pool would typically cost a fraction of that. Whether the premium is worth it depends on how much you value the softer water, reduced skin irritation, and lower chemical smell.
Using Backwash Water in the Garden
One practical advantage over traditional saltwater pools is that magnesium pool backwash water is safer for your garden. Sodium chloride from saltwater pools can damage soil structure and kill plants over time. Magnesium, by contrast, is a nutrient that plants actually need. When diluted at a ratio of about five parts fresh water to one part backwash water, magnesium pool water is generally safe for irrigation on grass, household plants, and garden soil. Some pool owners direct diluted backwash into rainwater tanks for outdoor use. Local council regulations on backwash disposal vary, so checking your area’s rules is still a good idea.
Who Benefits Most From a Magnesium Pool
The people who get the most out of a magnesium pool are those who swim frequently and notice the effects of chlorine on their skin, hair, and eyes. If you or your kids deal with eczema, sensitive skin, or dry skin that gets worse after swimming, the mineral blend can make a real difference in comfort. Swimmers who dislike the chemical smell and taste of traditional pools also tend to prefer the experience.
If you rarely swim, mostly use the pool for occasional entertaining, or don’t have skin sensitivity issues, the added cost of magnesium minerals over plain salt may not feel justified. The water is still chlorinated, and the pool still requires regular upkeep. The benefits are real but incremental, not transformative, for someone without specific skin concerns or strong preferences about water feel.