6 Hot Tub Chemicals You Should Always Have

If you're like most spa owners, you probably have more than just six spa chemicals on hand. There is often a larger collection of various spa treatment products, including sanitizers, balancers, clarifiers, cleaners and other specialty chemicals.

Every spa is different in terms of what is needed to maintain optimum water chemistry. Things like frequency of use, number of users, cleanliness of users, filter efficiency, pump run times, fill water quality and Mother Nature can all call for different spa chemicals at different times.

However, there is a core set of chemicals that spa owners should always keep in stock. You will still need to use others from time to time. But these six essential spa chemicals are used more often than others, and you should keep plenty on hand.


When it comes to spa care, it's best to remember the ABCs - algae, bacteria and contaminants. It's important to keep these controlled on a daily basis with high quality spa sanitizers. When hot tubs first came on the scene, almost everyone used bromine tablets as the primary sanitizer, and it is still the most popular option for spa owners today. Bromine tablets are used with a bromine booster to build up a bank of bromide ions, which can be easily regenerated by simply adding a shock oxidizer to the spa.

Chlorine tablets are not used as a spa sanitizer because they dissolve too slowly, lower pH and raise cyanuric acid levels. Chlorine tabs are only meant for swimming pools. However, granulated chlorine, such as Spa 56 by Leisure Time, dissolves quickly and maintains a chlorine residual for 5-7 days.

Many modern spas are equipped with ozonators, which supplement sanitation and allow for much lower levels of bromine or chlorine. You can also use a mineral stick or or other mineral product to achieve lower chemical levels in the water. Two popular mineral stick brands include Nature2 and FROG. FROG also has two models of popular floating sanitizers - the traditional Serene bromine + mineral system and the new, low maintenance chlorine + mineral system called @ease.


Spa shock belongs in a class of chemicals known as oxidizers, meaning they will oxidize contaminants in the water, pipes and filter. Although your spa water may be clear, at any given time there may be various "ABCs," byproducts and other particles that reduce sanitizer performance and filter effectiveness. Spa shocks destroy everything in the water, both inert particles and pathogenic organisms.

Shock your spa after each use, or every 7-10 days, whichever comes first. Shocking regularly is important to kill bacteria that may have escaped your daily sanitizer. It also helps reduce the build-up of oils, soap, skin, dust and other particles that enter the spa naturally. You can use either chlorine spa shock or non-chlorine spa shock (MPS) - it's up to you! Both are very effective. Multi-purpose MPS shock, such as Zodiac Cense, combines the benefits of a powerful shock with relaxing aromatherapy.


Spa clarifiers are positively charged polymers. They are strongly attracted to negatively charged particles, which are often the culprits of cloudy spa water. Using this law of attraction between the two charges, clarifiers work by forming large clumps of very small particles that would normally pass right through your spa filter. These larger particles are easier for your filter to trap, which helps clear up cloudy water faster.

Clarifiers like Leisure Time Bright & Clear make the water more pure by removing dissolved solids, which increases the effectiveness of your sanitizers and shock. This, in turn, makes your spa water last longer, increasing the length of time between water changes. In addition to its clarifying properties, Rendezvous Protect Plus uses a stain and scale prevention additive. There's also Rendezvous Natural Clear and Leisure Time Enzyme, which use natural enzymes to break down and remove oils and soaps from spa water.


At any given time, you may need either pH increaser or pH decreaser, but most people typically need the latter. Spas and hot tubs are small bodies of water, and with regular use, pH tends to rise in most spas. When pH rises above 7.8, sanitizers become less effective, and scale can form more easily. High pH is also an ideal breeding ground for algae and bacteria.

Spa pH should be maintained in the 7.2-7.6 range, which is just slightly basic. If you are having trouble adjusting your pH, or if the pH is very erratic and changes fast and often, test the total alkalinity of the water. Total alkalinity between 80-120 ppm is best to provide a buffer for the pH level, and helps it remain steady for longer periods. Add alkalinity increaser if below 80 ppm, or use pH decreaser to lower alkalinity levels higher than 120 ppm. A pH balancer can also help keep the pH within the ideal range for a longer period of time.


Hosing your spa filter clean will get most of the big stuff. However, it won't easily remove oils and mineral scale, which clog up the pores of spa filter cartridges. In such cases, the water pressure can push oil and minerals deeper into the fabric fibers, contributing to early failure.

Spa filter cleaners gently lift oils and mineral scale with a combination of mild acids and degreasers. Rendezvous Filter Fresh and Leisure Time Filter Clean are a couple of the more popular filter cleaner options, as is Natural Chemistry Filter Perfect. Just soak your cartridge in a bucket of water with the recommended amount of filter cleaner added. You can also use a spray-on filter cleaner and let it sit for a few minutes before rinsing clean.


This one doesn't need a long explanation. If you regularly condition the marine grade vinyl on your spa cover, it will look better, stay cleaner and last longer. Clean your spa cover first with a mild dish soap and a sponge to clean surfaces.

After drying, apply the spa cover conditioner to seal and protect the vinyl from rain, dirt, snow and sun. Regular applications of conditioner can add years to your cover's lifespan by preventing breakdown, fading, cracks and tears in the outer vinyl surfaces. Some cover conditioners come packaged as a handy disposable wipe for quick and easy cover maintenance, while others are available in a spray bottle. You can also clean and condition the cover using an all-in-one product like Leisure Time Cover Care and Conditioner.

You may need other hot tub chemicals from time to time, but these are what most would consider to be the "must have" core set of chemicals. These six groups of spa chemicals are needed (and purchased) most often. If you keep your chemical cabinet well stocked with the essentials, your spa will always stay sparkling and ready to use. If you're looking for a quick and easy way to stock up for months at a time, our 6-month spa care kits are the best way to stock up and save. Plus, you won't have to worry about buying more chemicals every few weeks.

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