When it comes to maintaining the water in your hot tub, nothing beats a good saltwater system. The added salt helps keep your skin smooth and youthful, while the reduced chemical load associated with saltwater systems actually increases the lifespan of your hot tub! For many, the question is not “Should I get a saltwater system”; it is “Which saltwater system should I get?”
When talking about saltwater spas, people typically are referring to chlorine or bromine generators that use a reaction called electrolysis to create a sanitizer from either NaCl (Sodium Chloride – A.K.A. table salt) or NaBr (Sodium Bromide – an alternative type of salt). These systems are installed in a hot tub and are designed to automatically generate sanitizer, making the maintenance much easier on you.
Such systems are permanently installed in your hot tub, as they need access to the electricity and water flowing inside. Typically, a salt system will have a separate control panel and an additional unit referred to as a ‘cell’ that is attached to the plumbing of your spa after the water passes through the filters. They are automatically activated when your spa circulates water and provide a constant stream of sanitizer as long as it’s running.
The type of solid chlorine and bromine used to sanitize hot tubs are packaged as a compound that, after mixing with your spa water, turns into calcium. High calcium levels can damage your hot tub, and as a result, it is typical to recommend owners to change the water every 3-4 months. With a saltwater system, you don’t typically use those chemicals, so saltwater spas typically only get drained and refilled once a year.
It’s important to know that saltwater systems are not the be-all and end-all of water maintenance for hot tubs. You will still need to test your water every week to ensure your system is generating the right amount of sanitizer, and you will still need to adjust your pH and alkalinity levels manually – which means you will still need to add some chemicals to your spa. One should also be aware that the cells that actually generate the sanitizer are considered consumable, and will eventually have to be replaced eventually, even on the best systems on the market.
Freshwater Salt System
We’ll start with the most unique system first, The Freshwater system from Watkins Wellness. Freshwater is a new proprietary system exclusively found on select HotSpring and Caldera hot tubs. Of all the electrolysis-based saltwater systems, Freshwater has the lowest start-up cost, at just $399, and integrate directly with the spa’s main control panel to keep the overall design of their spas very clean. However, it should be noted that models capable of using the Freshwater system are already pre-plumbed for it’s use, so there is an extra hidden cost to the system that you will pay regardless of your choice to use the system.
Unlike every other salt system, Watkins has opted to create their system with user-replaceable cells. This is because you will need to replace them far more often than any other saltwater system; Freshwater cells last only four months before they consume themselves. Because of this, dealers only sell them in three-packs, which cost $349.
To calculate the five-year ownership costs, we simply add together the start-up cost with four containers of salt (as one is already included with the starter kit) and five replacement cell three-packs. Altogether it adds up to $2223.80
in.Clear is an increasingly common saltwater system offered pre-installed by hot tub manufacturers. The units are made by Gecko, who also designs the electronic control and safety systems used inside many hot tubs being produced today.
in.Clear has a number of unique features that make it stand out. Because it is typically used in spas that also use Gecko controls, high end spas may have the controls for the system built into the main control panel – though it is also very common to see them with separate controls as well. The unit also has a “bromicharge gage”, a system that tests the conductivity of the water to help you figure out how much salt you need to add to your spa.
We consider Gecko’s in.Clear system to be one of the best on the market, but it suffers from the same issue that most saltwater systems do; the cell does not last very long. In fact, some of the spa manufacturers who integrate this system into their spas refer to the cell as a “Sacrificial anode” and does not warrant that it works except on delivery. The cell is considered consumable, but it’s lifespan can sometimes be extended by cleaning it – a process involving removing the entire unit and pouring powerful acids into it.
To calculate the cost of this system, we simply take the estimated start-up cost at $849 and add the cost of salt (three packages of salt at $23.95 per each of the five years). Because the cell is likely to break down in this time, we also include $300 for a replacement cell, bringing the total to $1359.95
Whiteswan Salt System
Our saltwater system is slightly different from other systems out there. While it doesn’t offer water testing features or integration with your main control panel, it makes up for it with one of the best cell designs in the industry.
The traditional design for a saltwater cell uses two metal plates called an anode and a cathode. Electricity flows from the anode to the cathode, and sometimes part of the metal actually will follow the path as well. That means that the cathode will eventually become encrusted with corrosion while the anode will eventually completely wear away.
Our cell is different: it uses an array of six different plates that receive distributed alternating current. What that means is that none of the plates are purely anodes or cathodes, which reduces wear significantly. That’s why we offer the longest warranty on our cells – a full one year – since our cells will typically last between five and fifteen years. It also provides one extra benefit; there is typically no need to clean the cell with harsh acids.
To calculate the cost of running this salt system, we simply take the cost of the salt (the same as the in.Clear system, above) and the initial saltwater system, leading us to $1859.29
Unlike the other systems in this article, Aquafinesse does not require installation and does not use electrolysis to generate sanitizer. Instead, you simply add their proprietary solution to your spa every week. We consider Aquafinesse to be a manual salt water system as the solution consists mainly of seven different types of salt and actively has the same benefits of an electrolysis-based salt system.
Unlike the other systems in this article, you do need to add a very small amount of chlorine or bromine to your spa in order to keep it clean. However, the amount you need to use is greatly reduced as the Aquafinesse solution breaks up bio films, which boosts the efficacy of your chosen sanitizer. It also has a powerful coagulant that helps your filter collect minerals, removing them from your water and helping you get the long span between drain/refill cycles that saltwater systems are known for.
Aquafinesse has a few smaller benefits that differentiate it from the automatic saltwater systems. The solution contains a buffer that helps maintain your pH, so you will not need to add pH increaser and decreaser as often. Because it attacks bio films, it actually cleans the inside of your hot tub’s plumbing as well. The solution itself actually smells good; it has often been described as smelling like lavender. And if you like how it works on your hot tub, Aquafinesse scales up to pool sizes as well, where it will also replace your algaecide.
Aquafinesse is typically sold in a kit with two one-liter bottles of solution and a small bottle of sanitizer, all of which will last you between four and six months depending on how big your hot tub is and how much you use it. You may also get the bottles individually or purchase an “all-purpose” kit that replaces the sanitizer with their own brand of filter cleaning tablets.
Calculating the costs of Aquafinesse will depend on how much water you fill your hot tub with and how much it is used. For smaller tubs with less use, a single kit can last up to 6 months, leading to a total cost of $1499.90. With heavy use and larger tubs, it usually lasts at least 4 months, leading to a total five-year cost of $2249.95.
The saltwater system you choose for your hot tub can lead to vastly different experiences; we recommend to consider how each one will affect how you take care of your spa. The in.Clear system’s bromicharge gage makes it excellent for people who don’t want to spend a lot of time trying to figure out the propper amount of salt to add to their spa, but the type of maintenance it requires may not be for everyone. For most people, we recommend our own Whiteswan salt system, as it does not require as much maintenance and has a longer-lasting cell, which makes it the least expensive system to operate over longer periods of time.
For those who prefer a lower starting cost, Your best options are either to use Watkin’s Freshwater system or to use Aquafinesse. Freshwater, however, is only available on a very small number of hot tubs and will cost the most to run. Either option will cost much more in long-term installations than the other salt systems discussed.