Hot Tub Chemicals 101

There are many different manufacturer/brand, and names of hot tub chemicals. Typically each manufacturer produces the same type of chemicals as another, some like SpaBoss, produce a higher quality product, meaning you won’t run through products quite as quickly, and SpaBoss chemicals will work longer, and harder than others. Distinguishing between the names of chemicals and what their purpose is, gets a little more complicated, especially with terms such as; TA, pH, etc. Hence, the purpose of this article; to give you, the end user, a little more insight as to why you’re adding which chemicals, and when. Let’s get started!

1) Sanitizers
Every hot tub user wants clean water, and to enjoy their hot tub without worrying about the bacteria, fungus, mold; or other contaminants in the water with you. This is why you use a Sanitizer. Two common types of sanitizer are; Chlorine, or Bromine. Sanitizers are essential in your hot tub to ensure the water stays clean, and to minimize the risk of skin irritations; or worse, mold and fungus taking over your hot tub. Keeping a sufficient level of sanitizer at all times in the hot tub, regardless of temperature outside, temperature of water, and how tightly closed the hot tub is; the sanitizer will work to destroy all contaminants in the water.

Chlorine is available in puck form, which you add to a floating dispenser; or granular form, which you sprinkle into the water. Granular form is a bit less convenient, as you add it by hand and may have to do so more often to keep levels up. Bromine is also available in both, pucks or granular form.

Chlorine is cost effective, easy to manage and apply, and an aggressive bacteria killer. Some people dislike the “smell” of chlorine, or have skin sensitivities to it; therefore, choose to use Bromine. Bromine works differently than chlorine as it’s more effective in killing certain types of algae, and keeps killing bacteria after an ‘attack’, like chlorine. You can read more on the differences between chlorine and bromine in our article here.

Chlorine levels in a hot tub are recommended to be in the 1-3ppm range, whereas bromine levels should read between 3-5ppm.

2) Shock (Oxidizer)
All hot tubs need to be shocked regularly as part of routine maintenance. Shocking agents are also classified as a type of sanitizer, but are used differently. Spa shocks are quick dissolving and fast acting, and used for killing anything your sanitizer has missed, or to supplement your sanitizer. For chlorine users, the shock oxidizes the dead (or combined) chlorine along with body oils, sweat, dirt, etc. For bromine users, shocking recharges the non-working bromides and gets them destroying bacteria, as well as getting rid of the oils, sweat, dirt, etc.

There are two different types of shock, chlorinated or non-chlorinated. Non-chlorinated shock can be used in chlorine or bromine hot tubs. Shocking should be done after heavy bather loads, or even a small amount after every use; or as a weekly treatment to maintain water clarity and sanitation. You can also give your water a shock treatment for other water issues such as; kill algae, eliminate foul odors, water discoloration, and poor clarity.

Make sure you follow the dosage instructions on the container and make sure you know the water capacity of your hot tub to ensure you’re using the right amount.

3) Balancers
Balanced water levels refer to having your chemical readings all within proper ranges. Balancing chemicals consist of Alkalinity increaser, pH increaser/reducer, and Calcium Hardness increaser.
Alkalinity, aka TA, is a pH stabilizer which helps your pH levels from fluctuating wildly. Alkalinity should be adjusted first to the correct range, and then pH should be adjusted. If both, TA and pH are low, adding alkalinity increaser will increase both, but make sure to check pH to ensure it reached to the appropriate level. If both are high, pH decreaser will lower both levels. Low TA and pH mean more acidic water, which can cause damage inside the tub, especially the heater. High TA and pH can cause scaling which will also damage the heater and anything else the water flows through. Proper levels of TA are between 100-150 ppm and pH between 7.2-7.8.
Calcium Hardness; or Total Hardness measures the amount of calcium and magnesium dissolved in the water. When within range, it prevents the water from eating away at the hot tub’s shell and plumbing. If Total Hardness is too high, you may notice your water may not be able to dissolve chemicals properly, and can lead to scaling on the sides of your tub, in the plumbing and can also lead to cloudy water. If Total Hardness is too low, the water can cause damage to the tub. It can eat away at the plaster, and corrode your plumbing, jets, and everything else it touches. Raising the Total Hardness is simple; just add the proper amount of Cal-Rise according to the instructions on the container. High Total Hardness readings can be difficult to reduce, so be cautious that you follow the instructions and dose accordingly. Total Hardness range is between 200-400 ppm.
pH level measures the acidity of your hot tub water. High pH readings are considered to be basic or alkaline and cause your sanitizer to work poorly and can lead to cloudy water, and scaling. Low pH readings indicate your water is too acidic, and can also cause the sanitizer to work poorly, as well as; causing your eyes to burn and skin irritations. Low pH can also reduce the ability to control the TA. Acidic water can also cause damage to the hot tub. Proper level of pH is between 7.2-7.8

Water test strips can give you sufficient readings of your water balance, including the sanitizer level, TA, Total Hardness, pH and even the Combined Chlorine levels; and most Spa Dealers have water test systems that can read more accurately, and give you recommendations on what to add, and how much.