Filling your swimming pool with hard water doesn’t only make your pool look bad – it can also significantly damage your pool equipment.
The best method of softening pool water is to use a water softener hooked up to your plumbing system. This will give you access to soft water whenever you need it.
In this guide, we’ve shared all the important information on how to soften pool water. Pool owners, take note.
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🚰 Top 4 Methods of Softening Pool Water
There’s only one 100% effective method of softening the water in your pool: using a water softener.
Water softeners use water softening salts to remove hardness minerals, decreasing magnesium and calcium levels in a water system. These point of entry systems prevent scale in your entire home, including all pipes and water-using appliances.
You may come across chemical water softener products at your local pool store. These can be fairly effective in treating hard water, but they’re not as consistently capable as water softeners.
Water softeners physically remove calcium and magnesium, which chemical water softener products can’t do.
If you don’t want to spend money on a water softener, you can use a pool flocculant to encourage the excess calcium in your water to clump together. You can then vacuum your pool to remove the clumps. Make sure you turn off your pool pump and filter before adding floc to your water.
This method is a suitable short-term solution for reducing water hardness in your swimming pool, but it’s fairly time-consuming over an extended period.
If using pool flocculant isn’t effective enough, you can use muriatic acid to balance your pool’s calcium content as a last resort.
Muriatic acid doesn’t actually soften water or reduce calcium or magnesium hardness. It’s used to raise the saturation level of water, which balances the water parameters.
📑 How to Soften Pool Water: Step by Step
Follow these six steps to enjoy soft water in your swimming pool.
Step 1: Measure your Water Hardness
Before you begin, it’s helpful to know how hard your pool water is. You need to know that your water quality issues are actually caused by calcium hardness and not something else.
If you fill your pool with water from a garden hose that’s connected to your plumbing supply, you can check your Water Quality Report (or Consumer Confidence Report) to learn about your water hardness level. This report should be provided to you annually by your water supplier.
Note: well owners don’t receive an annual report.
To get the most accurate reading of the hardness level of your water supply, use a water hardness test kit. Buy a DIY kit with test strips that give you an instant result. Testing your water takes a matter of minutes and can give you the knowledge you need to choose a softening solution.
📌 Water hardness between 3.5 and 7 GPG is considered moderately hard, and anything over 7 is considered hard. Check out this article for more information on how water hardness is measured.
Step 2: Outline Your Budget
Once you’ve established that you’re dealing with hard water, it’s time to outline your budget for a water softening method.
Most suitable hard water treatment systems are priced between $600 and $2,200. Some are more expensive than this, but they don’t usually offer more value. We recommend spending at least $800-1,000 on a water softening system to make sure you don’t end up disappointed with the quality.
Also consider your maximum annual budget. Salt-based softeners need to be topped up with water softener salts, so they’re more costly than salt-free water conditioners.
Step 3: Buy a Water Softener
After setting a budget and with your water hardness data to hand, you can begin shopping for a water softener.
We recommend salt-based ion exchange systems because they soften water by physically removing hardness minerals. During ion exchange, calcium ions and magnesium ions are exchanged with water softener salt (sodium ions). If you correctly size the system for your needs, it’ll eliminate hard water.
Water conditioners retain calcium and magnesium in water, but they prevent scale by conditioning these minerals – giving them a crystallized coating that prevents them from sticking to your pool walls as scale. Many people are extremely pleased with the performance of water conditioners, and the systems don’t need to be topped up with water softening salts. But because they don’t actually soften water, you won’t be able to tell from a water test whether or not your conditioner is working.
Step 4: Install the System
Finally, install your chosen water softener in your home. The ideal location to install a water softener is at your main water line, upstream of your water heater. This means your entire home will benefit from soft water, as well was your pool.
Depending on the type of water softener you install, you might need a professional plumber to install the system for you. The installation process is fairly complex for all systems – you often need to cut into your main water line and do some soldering.
The softener should be ready for use as soon as you’ve installed it and added water softener salts to the brine tank. Make sure the bypass valve is activated to allow water to flow in and out of the unit.
Step 5: Drain and Fill Your Pool
Once you’ve installed your water softener, you can fill your pool with softened water and enjoy a scale-free swimming experience.
First, drain out the existing water (if applicable). Use your usual method of draining.
You may choose to clean your pool while it’s empty. The more limescale you can remove now, the better your water quality in the long run.
Then switch on your hose (or whatever you use to fill your pool) and allow the water to fill to the fill line.
Some hoses aren’t connected to a point in your water supply that receives soft water. In this case, connect your hose in your kitchen or laundry room to guarantee access to soft water.
Be careful not to overwork your water softener. Most systems can consistently deliver softened water for 8-12 hours, depending on their capacity. Check with the water softener’s manufacturer if you’re not sure.
Step 6: Re-Test Your Water
Finally, once your pool is full, conduct another water test. Your water should be significantly softer than it was in the first test.
If your pool’s total hardness is still high, your water softener probably isn’t set up properly.
📌 Make sure to add water softener salt regularly to the brine tank to keep the system working correctly.
🔎 Effects of Hard Water in Swimming Pools
Wondering what’s so bad about hard water in your swimming pool? Here are some of the worst effects of hard water:
- Aesthetic issues. Hard water leaves scale deposits on all surfaces it touches. Over time, the gray-white chalky mineral residue will build up on your pool tiles and sides, giving them a dull, unclean appearance. Calcium carbonate and magnesium minerals can also make water look cloudy and dirty.
- Damage to pool components. Limescale also forms in your pool’s filters, pumps, and other equipment. This buildup reduces the efficiency of your equipment and significantly shortens its lifespan.
- Increased maintenance requirements. If you fill your pool with hard water, you’ll have to schedule more frequent maintenance, including pool cleaning, parts cleaning, and more. Hard pool water requires more trips to the pool supply store for repairs and replacement parts compared to soft water.
- Dry hair and skin. Swimming in hard pool water will dry out your hair and skin. Water hardness minerals form a layer of residue on your skin and hair, leading to irritation, flakiness, and clogged pores.
🧫 Other Common Swimming Pool Contaminants
Calcium hardness might not be the only issue with the water in your pool. Other aesthetic contaminants in swimming pools include:
- Iron and manganese (orange or red-brown stains)
- Tannins (tea-like coloration)
- Sediment or floating particles (most common in outdoor pools)
- Copper, low pH level (blue-green stains)
There are several invisible contaminants found in swimming pools, too. Poorly-maintained pools and hot tubs may harbor disease-causing bacteria, so make sure to maintain your pool regularly and retain optimal chlorine levels.
🧠 How to Soften Pool Water: FAQs
What happens if pool water is too hard?
If pool water is too hard, you’ll notice issues like cloudy water, chalk-like deposits on the pool surfaces, and clogged or inefficient pool components. Hard water isn’t dangerous in swimming pools, but it can have expensive aesthetic effects.
Will baking soda soften pool water?
No. Baking soda can be used to maintain your pool’s optimal alkalinity and pH, but it isn’t designed to produce soft water. The only effective water softening option is to use a water softener system, which exchanges magnesium and calcium hardness ions with sodium ions.
Should pool water be softened?
It’s not an essential requirement to soften your pool water. However, there are notable benefits of having soft water in your swimming pool: your hair and skin will feel better after swimming; and your pool will look cleaner and require less frequent maintenance or replacement parts.
Will water softener salt work in pools?
Yes, you can soften pool water with water softener salt. Keep in mind that you can’t simply add the salt to the water and expect it to get softer – you need a water softener, which will exchange magnesium and calcium minerals with sodium ions to soften your water before it enters your pool.
What’s the ideal water hardness for swimming pools?
Different swimming pools have different ideal hardness ranges. If you have a concrete or plaster pool, a water hardness range of 200-275 is fine. If your pool is lined with vinyl or fiberglass, you need a particularly low water level of 175-225 parts per million (PPM).
Can I put water softener salt in a pool?
Yes, you can put water softener salt in a pool for antiseptic purposes. However, pool salt is still the best option because it’s pure, whereas some types of water softener salt are mixed with impurities that could clog your pool pump or filter.
Can I use pool salt in a water softener?
No, you shouldn’t use pool salt in a water softener. Pool salt has large crystals that might clog your water softener’s valves. Pool salt is also known to dissolve more slowly than water softener salt, reducing the effectiveness of the softening process. If you want your softener to last for as long as possible, stick to using water softener salt in your brine tank.