Hot Tub Chemistry

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This took us a little while of collective thought at Hot Tub Connection

Achieving the Perfect Hot Tub Water Balance:

Proper water balance is the key to keeping your hot tub water sparkling clean and ensuring its longevity. A well-balanced hot tub not only promotes the effectiveness of your sanitizer but also keeps the system and users safe and comfortable. Let’s dive into the essentials of water balancing!

While calcium hardness doesn't directly impact the effectiveness of your sanitizer, it plays a crucial role in maintaining the health of your hot tub. If calcium levels are too low, the water will "steal" calcium from surfaces it contacts, including your tub shell, plumbing, and pumps. Over time, low calcium can damage acrylic surfaces. On the other hand, if the calcium level is too high, scaling can occur on equipment, especially the heater element, leading to cloudy water and reduced equipment lifespan.

• Ideal Calcium Levels: Keep your calcium levels in check. If the levels exceed 400 ppm, it’s time to drain and refill your hot tub. While stain and scale prevention products can help temporarily, they don’t address the root cause.

To increase calcium levels, simply add a calcium booster according to the instructions on the container.

Now, let’s focus on the two most critical components for sanitizer efficiency—Alkalinity and pH.

• Why Alkalinity Matters: While your sanitizer (chlorine or bromine) is unaffected by alkalinity, the pH level is directly impacted by it. Proper alkalinity helps stabilize pH, preventing fluctuations that can reduce the effectiveness of your sanitizer.
• What’s the Difference? Total alkalinity is a measure of your water’s ability to neutralize acids, while alkaline water refers to water with a high pH (more basic than acidic). Though related, these two concepts are distinct.
• Alkalinity Levels: Maintain your total alkalinity between 80-120 ppm for optimal pH stability. If your pH is on the higher side, add enough alkalinity increaser to bring the alkalinity to 120-150 ppm. Then, adjust the pH. If your pH is low, raise the alkalinity to the desired 80-120 ppm range.

A consistent and balanced pH is essential for your sanitizer to work at its best. The pH level of your water should be maintained between 7.2 and 7.6. Anything above 7.6 reduces sanitizer effectiveness, so it’s best to keep the pH slightly below this threshold.

• How to Adjust pH: To bring the pH level within the ideal range, add a pH reducer or pH increaser. Test your water regularly to ensure the pH is perfectly balanced.

Once your water is properly balanced—calcium hardness, alkalinity, and pH are in perfect harmony—your sanitizer will be able to do its job efficiently, keeping your water clean and your hot tub in great shape for relaxation and enjoyment!

Sanitation/ Oxidation

When it comes to sanitizing your hot tub, there are two main options: chlorine and bromine. While both are effective, there are a few key differences that can help you choose the best sanitizer for your needs.

A common myth is that bromine works better in hot water than chlorine. This is simply not true! Both sanitizers have their strengths, but here’s the reality:

• Stabilization: Bromine cannot be stabilized, while chlorine can be. This means that chlorine benefits from stabilizers, which prolong its effectiveness by preventing UV breakdown. Bromine, on the other hand, loses its potency rapidly when exposed to UV radiation and cannot be stabilized in the same way.
• Speed: Bromine is slower-acting than chlorine, which is why hot tubs often require higher bromine levels to properly sanitize the water. Some believe this slow-acting nature is gentler on the water, but there’s no scientific evidence to support that claim.

While both sanitizers are effective, we recommend stabilized chlorine in granular form—specifically, dichlor.

• Dichlor vs. Trichlor: Chlorine is available in two main forms—dichlor (granular) and trichlor (tablet form). A common misconception is that a chlorine tablet dispenser is the best method for maintaining proper chlorine levels. However, dispensers release chlorine steadily, whether or not your hot tub actually needs it. This means your chlorine levels can spike during periods of low usage or be insufficient during heavy use. Plus, trichlor is highly aggressive and can damage your hot tub’s surfaces, including the jets and pillows.

• The Better Alternative: Dichlor chlorinating granules offer a more controlled solution. Once you’ve determined how much dichlor raises your chlorine level, you’ll know exactly how much to add whenever your levels dip. This method is more efficient and easier to manage than relying on a dispenser.

For hot tub owners looking to reduce their chlorine levels, a high-quality enzyme system is a game-changer. Enzymes can lower chlorine consumption by up to 80%, making them ideal for those sensitive to chlorine. This approach is much more effective than switching to bromine, which still requires higher levels of sanitizer.

After testing over a dozen enzyme systems, we found Spa Marvel to be the best option. By simply adding a bottle every three months, you can maintain chlorine levels below 1 ppm, eliminating unpleasant odors, fumes, and skin irritation. In fact, many users have reported improvements in their skin conditions after using Spa Marvel.

Once your hot tub water is sanitized, the next critical step is oxidization. This is where chlorine or bromine works to neutralize contaminants. However, the process isn’t complete just yet. After the sanitizer attacks bacteria, it forms chloramines—molecules that are no longer harmful but still linger in the water. Chloramines produce that familiar "pool smell" and indicate that there are still contaminants in the water.

To effectively remove chloramines, you need to shock the water. This involves adding a shock treatment and leaving the cover open to allow the chloramines to gas off.

There are two types of shock treatments for hot tubs: chlorine-based and non-chlorine-based.

• Chlorine-Based Shock: While effective, chlorine-based shock adds a large dose of chlorine to the water, raising levels drastically. You’ll have to wait for the chlorine levels to drop back down before using the hot tub again, which can be a hassle.
• Non-Chlorine Shock: A much better option is non-chlorine shock, which uses ingredients like sodium-monopersulphate to break down chloramines without raising chlorine levels. This method allows you to get back in the water within an hour and avoids throwing your sanitizer levels out of balance. Just remember to keep the cover open for at least 20 minutes after shocking to ensure the gases escape properly.

There will be times when you'll need to super-chlorinate your hot tub—such as after heavy use or if the water becomes cloudy. Super-chlorination involves raising the chlorine levels to about twice your normal level, not the extreme 10 times that happens during shocking. This can be easily done by adding a double dose of dichlor granules and allowing the water to circulate for 4-6 hours before adding shock.

To achieve crystal clear, gentle water with no odor or fumes, we recommend the following:

1. Stabilized Chlorine Granules (Dichlor) – for precise, controlled chlorine levels.
2. Non-Chlorine Shock – for effective oxidization without overloading the water with chlorine.
3. Spa Marvel Enzyme System – to maintain low chlorine levels and keep the water smooth and skin-friendly.

With this combination, you’ll enjoy a clean, inviting hot tub every time you use it—without the harsh chemicals or strong odors.

Tips

Proper hot tub care ensures a relaxing, safe, and clean experience every time you use it. Here are some essential tips to help you get the most out of your new hot tub:

If your hot tub is equipped with a circulation pump, this tip may not apply, as the pump will filter water continuously, 24/7. However, if your hot tub does not have a circulation pump, it's crucial to learn how to set the filtration cycles.

• Advanced Topsides Panel: If your panel is more advanced, you can set specific start and stop times for filtration.
• Basic Topsides Panel: On simpler panels, you will set the filtration duration, such as F2 or F4, which corresponds to 2 hours or 4 hours of filtration every 12 hours.
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We recommend filtering for about 3 hours every 12 hours, though you can increase this time after parties or if the water needs extra attention.

Water quality is essential when starting with a fresh hot tub, especially if you're using well water or municipal water with high mineral content. These minerals can cause discoloration and make water balance challenging.

Using a high-quality X-10 Filter can help remove contaminants and heavy metals, ensuring you start with pure, clean water.

• The X-10 filter is designed to handle up to 10,000 gallons of water—enough to fill an average hot tub about 30 times! This makes it an excellent long-term investment, lasting 10-15 years with regular use.

It's a common misconception that adjusting your hot tub temperature can save energy. In reality, reducing the temperature causes the heater to turn off, and when you increase the temperature again, the heater will work full-time to bring the water back to the desired level, using more energy than simply maintaining a steady temperature.

• Tip: Keep your hot tub at a consistent temperature for the best energy efficiency. Make small adjustments for comfort, but avoid large temperature swings to save on energy.

Foam in your hot tub is often caused by bacteria or contamination, but it can also result from detergent residue left on bathing suits. Even a small amount of detergent can dissolve into the water, leading to foam buildup.

• Pro Tip: Simply rinse your bathing suits in warm water without detergent and allow them to dry naturally. This will help prevent foaming and keep your water clean.

To keep your hot tub water clean and the filtration system working efficiently, regular filter maintenance is essential:

• Weekly: Remove your filter(s) and rinse them thoroughly with a garden hose. Do NOT use a pressure washer, as it can damage the filter fabric.
• Monthly: Deep clean your filters with a quality filter cleaner, such as Spa Marvel Filter Cleaner, to remove stubborn debris and build-up. After cleaning, rinse thoroughly and replace the filter back in the tub.

By following these simple but effective maintenance tips, you’ll enjoy a pristine, relaxing hot tub experience.