Everything You Need to Know About Magnesium Pools

February 5, 2024

Once you own your dream pool, the next decision to make is how you are going to keep it clean. Chlorine has historically been the solution of choice, but more pool owners are turning to magnesium to keep their pools sanitised.

Magnesium offers relief from the red eyes and dry skin commonly associated with chlorine pools while making the water feel silky smooth. Also known as mineral pools, the collection of minerals, including magnesium chloride, sanitise without the same harshness as chloride.

Most mineral pools contain magnesium, which is why the terms ‘magnesium pool’ and ‘mineral pool’ are generally used interchangeably. At any time, you can switch to a magnesium pool without having to change your pool or filtration system.

What magnesium pools are all about

In terms of design and build, Magnesium pools are just like any other. They don’t require different build materials or special installation. Rather, they are swimming pools with added minerals in the water with magnesium being a key player.

There are two main components to a successful magnesium pool—magnesium, which is a mineral, and chloride, which is an electrolyte. Together, they make magnesium chloride which is a compound naturally found in seawater and brine.

Magnesium chloride is the superstar that sanitises your pool while making it feel better, smell better, and be more enjoyable overall. In addition to magnesium chloride, a small amount of chlorine and bromine are required for magnesium pools to kill bacteria and viruses and help prevent algae blooms.

The levels of chlorine and bromine required in a magnesium pool are significantly lower than what would be used in a chlorine pool. The amount is so little that it doesn’t affect the water quality. With this amount of reduced chlorine and bromine levels, the water in a magnesium pool is better for your skin, eyes, clothing, and doesn’t come with that notorious potent chlorine smell.

Why so many people prefer magnesium swimming pools

Magnesium pools are favored over chlorine pools for a reason. The water feels ‘softer’ and is often described as ‘silky,’ plus the overall experience is just simply more enjoyable.

Who likes the smell of chemicals, the stinging of the eyes, and—for those who are blonde—a green tint to the hair? Not many, and a magnesium pools provides a clean swimming experience without these unwanted side effects.

Magnesium pools heavily reduce the need for chlorine and bromine by about 50%, which removes the smell of chlorine from your swimming experience.  Overall, magnesium pools are easier on the senses and gentler on the skin, which is ideal for anyone with skin conditions like psoriasis or eczema.

On top of creating a clean and enjoyable swimming experience, magnesium is actually good for our skin and overall health. It’s believed to be absorbed through the skin and is essential for proper bone, joint, and muscle health. It also helps:

  • Relax nerves and muscles
  • Detoxify the body
  • Reduce stress, anxiety and depression
  • Improve sleep

Magnesium is so important for good health at all ages

Minerals are an essential component of our overall health, with magnesium being among the most important. Our bodies use magnesium for over 300 life-essential functions, including:

  • protein synthesis
  • muscle and nerve function
  • blood glucose control
  • blood pressure regulation

Magnesium is a crucial mineral for optimal health and is required for an array of basic, yet critical bodily functions. It’s unfortunate, however, that magnesium deficiency is growing increasingly common. Nearly half of Americans of all ages ingest less magnesium than the average requirement, spanning from males 71 years and older to both male and female adolescents.

Continuous low levels of magnesium in-take can increase the risk of illness over time by altering biochemical pathways. Simply put, you want to make sure you’re getting enough magnesium for optimal health.

According to a study published by the Epsom Salt Council, magnesium can be absorbed via the skin, potentially increasing levels in the body. This makes owning a magnesium pool a positive investment for the health of your entire family.

Since mineral deficiencies are common across generations, a magnesium pool can help introduce more essential magnesium minerals to you and your family, helping to:

  • Increase energy production
  • Improve the structural development of bone.
  • Promote synthesis of DNA, RNA, and the antioxidant glutathione
  • Improve nerve impulses, muscle contraction and normal heart rhythm.

If getting too much magnesium is a concern for you, don’t worry. Magnesium levels are closely controlled in the body and any excess magnesium will simply be excreted, eliminating any concern for ‘overdosing’ on magnesium from swimming.

Any pool can be converted to a magnesium pool

New or old, any pool can be converted to a magnesium pool independent of the material whether it’s made of concrete or fibreglass you don’t need a special type of pool shell, or a different pump or filter. Your pool, as it is now, can easily be turned into a magnesium pool.

The simplest way to make the switch to a magnesium pool is to talk to a pool maintenance expert. They can handle this process for you. If you prefer the DIY approach, there are a few steps involved in converting to a magnesium pool.

Test water hardness

The DIY approach to transforming your pool into a magnesium pool starts with testing water hardness.

If you’re starting with an empty pool, first test the hardness of your water source. If it’s above 225 ppm (275 for a concrete or plaster pool), use a hose filter when filling the pool.

Using a hose filter is always a good approach when filling or adding water to your pool. It helps remove and reduce other minerals, such as copper, which is ideal for maintaining the excellent quality of a magnesium pool.

Allow your chlorine and bromine levels to drop

Now, before adding minerals, it’s important to let your chlorine levels drop to 0.5 parts per million (ppm) or lower before adding minerals.

For bromine, let that level drop to 1 ppm or lower.

Don’t skip this step!

Test for Metals

Before using a pool mineral sanitizer, it’s important to test for metals so you know which ones your water source contains and how much. In this circumstance, you may want to take a sample to your local pool store for more detailed testing.

Pay attention to the test results. If the metal—especially copper—levels are high, it’s important to add a metal sequestrant to the water after you fill the pool.

Balance the Water

Once you have filled your pool and added a metal sequestration (if needed), it’s now time to get the water’s chemical balance in check. The best way to do this is by testing the water to get baseline levels with at-home test strips or a liquid test kit. Follow this order to test and balance your pool: alkalinity, pH, calcium hardness.

They should be in the following ranges:

  • Total Alkalinity: 100 ppm to 150 ppm, with 125 ppm being ideal
  • pH: 7.4 to 7.6, with 7.5 being ideal
  • Calcium Hardness: If you have a concrete or plaster pool, shoot for 200 ppm to 275 ppm. For any other type of pool, aim for a range of 175 ppm to 225 ppm.

Add the Minerals

Once you get the water balanced, you can add the pool mineral sanitizer to the skimmer, the floating dispenser, or the in-line system. We will go over this in further detail below.

Regardless of the type of pool mineral system you decide to use, follow the manufacturer’s instructions and change the cartridge when necessary.

Add the Supplemental Sanitizer

Now, it’s time to add supplemental sanitizer. Whether you’ve decided to use chlorine or bromine, add and measure a little at a time, while testing in between.

Be cautious and keep testing until you have reached the correct level:

  • Chlorine: 0.5 ppm
  • Bromine: 1 ppm

How Much Magnesium Mineral Should You Add?

Assuming you’re starting from scratch (at 0 parts per million or ppm for short) with a newly filled pool containing fresh water from your garden hose the following table will help you to gauge the magnesium minerals you should add. Be aware though that this is a rough guide and you should test your water properly before adding any minerals and as you approach the suggested limit to ensure you reach the right levels.

Water Volume in Your Pool
0 ppm30 kgs60 kgs90 kgs120 kgs150 kgs180 kgs210 kgs240 kgs
500 ppm20 kgs40 kgs60 kgs80 kgs10 kgs120 kgs140 kgs160 kgs
1000 ppm20 kgs30 kgs50 kgs70 kgs90 kgs100 kgs120 kgs150 kgs
1500 ppm10 kgs20 kgs30 kgs40 kgs50 kgs60 kgs70 kgs80 kgs
2000 ppm10 kgs20 kgs30 kgs40 kgs50 kgs60 kgs70 kgs80 kgs
2500 – 3500 ppm1/2 Bag10 kgs15 kgs20 kgs25 kgs30 kgs35 kgs40 kgs
4000 ppm0 kgs0 kgs0 kg10 kgs10 kgs20 kgs20 kgs20 kgs
4500 ppm0 kg0 kg0 kg0 kg0 kg0 kg0 kg0 kg

How to add the pool mineral sanitizer to your pool

Adding minerals to your pool to transform it into a magenesium pool doesn’t require a new pump and special filters. Instead, there are a few simple devices for you to choose from that will help you get the job done.

  • In-Skimmer Pool Mineral Systems: These are small baskets designed to sit in your pool skimmer. You put the minerals inside and the skimmer will draw water through them, adding it to your pool.
  • Floating dispensers: These dispensers float freely in your pool with mineral and chlorine cartridges completely submerged. Once the cartridge is empty, these dispensers usually turn on their side, indicating it’s time for a new cartridge.
  • Inline systems: This is usually a small unit that gets integrated into your pool’s existing plumbing system, allowing the water to pass through a mineral cartridge. Once installed, it’s important to be mindful and replace the cartridge when depleted.

The drawbacks of a mineral pool

There are pros and cons to everything. Even the most enjoyable experiences have a few inevitable cons. Magnesium pools are no different. So, let’s get into it.

What are the magnesium pool cons?

You’ll still need to use some chlorine and bromine

Mineral pools need a little help from chlorine and bromine to ensure your pool is as clean as possible. The levels of chlorine and bromine are less than 50% of what would be used in a chlorine pool; however, you will still need to use small amounts of both chemicals.

Maintenance will cost a little more

Compared to the costs associated with a chlorine pool, the combined expenses of pool minerals, chlorine and bromine for a magnesium pool will be slightly more expensive. The cost difference isn’t significant, but worth mentioning as a con. Alternatively, in some cases where pool chemistry is very closely monitored, mineral pools can even work out marginally cheaper.

Green oxidation stains

If your water has a high enough copper content, this can cause oxidation and leave green stains on your pool’s interior. Regardless if mineral products are advertised as being ‘stain-free,’ high copper content can still leave stains. To avoid this, you can use a filter on your hose when filling the pool and use a metal sequestrant to prevent the onset of stains.

Based on the feedback from magnesium pool owners, these problems are not a major cause of concern. When it comes to magnesium pools, it seems the pros far outweigh the cons.

Interested in adding a magnesium pool to your backyard? See our options here or contact us directly to find the right pool for you.