Trying to find out what your hot tub contractor is talking about? Read our glossary of terms for hot tubs to familiarize yourself with the acronyms, abbreviations and terms.
If the pH of the water in a hot tub is less than 7.0 or neutral, it is acidic. To modify the pH of hot tub water, chemicals such as pH plus and pH minus are utilized. It is important to note that when powerful acids are mixed with water, a large quantity of heat is created, thus always add chemicals to the spa water, never the other way around. If the pH in the hot tub is too high, add pH minus, which is an acid, directly to the hot tub water.
The thermoformed hot tub shells are made of high-quality material. This is a non-porous, long-lasting substance that is frequently reinforced with ABS or fiberglass. Acrylic is manufactured in the United States by Lucite, Aristech, and other companies. Other spa shell materials could include less expensive thermoplastics. The original tubs had a spherical wood, barrel-like structure.
The process of introducing air into a hot tub jet via a venturi. An air hose is frequently joined to the top or venturi port of a typical jet, and the bottom hole of the jet is connected to the water piping. As water is forced into the jet, air is drawn in to help the water travel. Aeration is also utilized in aquaponics and fish tanks.
An air pocket within the plumbing of a hot tub inhibits water from moving in the spa. The answer is to remove the air pocket, which is frequently accomplished by slightly opening a union to enable air to leave and then retightening carefully so that the union does not shatter. This type of air lock can occur in newly refilled spas. Did you know that on some Balboa systems, the 4 minute PR-Priming mode is not an automatic feature and that the spa is waiting for you to manually prime/start up all of the spa pumps?
Electro-mechanical switches are seen in vintage hot tubs and hot tub paks made by Len Gordon and others, where a button attached to an air hose causes a puff of air to move a mechanical switch on the circuit board.
Any of a wide variety of photosynthetic organisms found in aquatic or wet environments, ranging in size from single-celled diatoms to minuscule aquatic plants without roots that can grow on hot tub surfaces. There are various types of algae, including black algae, yellow algae, and green algae. A hose with standing water can frequently bring algae into the water in the first place. When filling the spa, use a pre-filter to prevent pollutants from entering the water. Low sanitizer levels may also be the blame for algae growth in a hot tub. Blowing winds can also introduce leaves, pollen, and other impurities into the spa. Another reason to cover the hot tub when not in use. If the spa has an algae problem, drain the water, superchlorinate/shock treat it, and even use a product like Ahh-Some to remove the contamination from the piping. Chlorine is an enemy of algae.
A spa and pool chemical that kills algae while simultaneously preventing its regrowth.
This term refers to the concentration of alkaline materials in water. These substances have the ability to buffer or modulate pH levels.
At all times, a range of 100-150 ppm should be maintained. Alkalinity is increased by Alkalinity Plus and decreased by pH Down.
Single-celled microbes that can thrive as autonomous organisms or as parasites in a hot tub. To keep hazardous microorganisms at bay, proper sanitization is essential. Hot tub folliculitis is a skin ailment caused by bacteria found in a hot tub. If you have biofilm forming in your hot tub plumbing lines, you should consider running a purge every now and again with a degunker/biofilm remover like Ahh-Some.
Water that is neither acidic nor basic in nature. In the context of hot tub water, the pH is kept between 7.2 and 7.6.
Furthermore, water is balanced when the pH, total alkalinity, and calcium hardness are all in sync.
It is truly balanced if the sanitizer level is correct.
When the pH of water exceeds 7.0, the water is alkaline. To rectify this problem, pH minus, an acid, is used to lower the pH to the acceptable range of 7.2-7.6. To avoid damaging equipment, hot tub water should be maintained relatively basic. This is also better for swimmers.
In a hot tub, biofilm can contain pathogenic bacteria, mold, parasites, debris, and other microorganisms. Because bacteria may adhere to hot tub nooks and crannies, even though a hot tub appears clean, there may be some “hangers on” that can be discharged into the water before the sanitizer can do its job. Biofilm can accumulate on the edges of seats, acrylic walls, the filtera region, the skimmer, the pump lines, the jets, the light fixtures, the air injectors, and anywhere else in the plumbing/PVC section. Biofilm can be removed from the tub using products from Ahh-Some and AquaFinesse. With Ahh-Some, you can remove accumulated biofilm in your hot tub piping.
Bromamines occur in the water for disinfection ((NH2Br, NHBr2 and NHBr3), and pH influences the amount of compounds created, thus it is critical to maintain optimum pH in a hot tub setting so that bromine can do its work.
Bromine eliminates microorganisms in hot tub spas. 1″ pills to chemical dispenser or floater are frequently added to spas.
When replenishing the spa, a packet of granular bromine is added to the water to create a bromine reserve without having to wait days for the necessary amount to dissolve from the feeder tablets.
Scale deposits that form on a hot tub shell and in the pipes as a result of a water chemistry imbalance or an excessively high pH. Stain and scale protection can be useful in this situation.
This measurement indicates the amount of calcium dissolved in the spa water. For hot tub spas, the optimal calcium hardness level is 180-250 ppm. If the pH is normal but the source of the problem is the water supply, use a prefilter while refilling the spa to filter out extra calcium. Scale can form if the water is too hard (more than 300 ppm). Metal components in the spa can be damaged if the water hardness is too low.
Calcium Hypo is a granular form of chlorine used in swimming pools but not suggested for use in spas due to the possibility of calcium deposits, scale, and discoloration.
Spa cartridge filters are replacement filters created from various filter paper/media and end-cap styles. Spa filters should be washed with a garden hose on a regular basis, submerged in an overnight filter bath every 3 months or so, and replaced once a year.
Stain and scale prevention agent that keeps water from turning yellow owing to excess metals in the water. As needed, use Metal Gone or other metal deposit prevention agents.
These chemicals are formed when chlorine reacts with pollutants in the water to form complex and odorous molecules such as ammonia (combined chlorine). This results in less free chlorine, therefore shock the water weekly or as needed to free up the chlorine rather than allowing the water to smell. Do you have eye and skin discomfort, as well as a strong chlorine odor? This may not necessitate adding more chlorine to the water, but rather freeing up the current chlorine using a shock treatment. Ozonators also aid in the reduction of chloramines because ozone is the most effective oxidant.
One of the two recommended hot tub sanitizers, available in granular, liquid, and chlorine puck forms (the other one is Bromine). Chlorine is used differently in pools and spas. Tri-chlor can be used in pools, but it should not be used in hot tubs. Di-chlor is chosen instead.
Balboa, Gecko, Hydroquip, and other manufacturers’ hot tub circuit boards keep the hot tub operating and heating. The circuit board is where the control panel connects in to regulate some of the hot tub’s characteristics. Fuse, relays, contactors, switches, jumpers, and wiring are all part of the single portion on the circuit board. Rather than replacing a specific on-board component, a repair may necessitate the replacement of the complete circuit board. Note the serial and component number of the circuit board on a sticker attached to it, as well as the software revision number on the main processor chip (EPROM) label.
A clarifier is a spa chemical that can mix particles in the water, causing them to coagulate (clump together) and then be filtered out by the filter cartridge.
This is the overall chlorine content of the water, including chloramine compounds that are no longer useful as a sanitizer. We truly want free chlorine to fight new contaminants and chemicals in the spa water.
A method of corroding metal coatings and fixtures by allowing the pH level to rise to a corrosive level (lower than pH 7 or neutral).
A cover lift enables a single person to easily remove and replace the spa cover. Bottom, side, or cabinet mounting options are available. Some cover lifters require clearance behind the spa where the cover goes, as well as on both sides of the spa where a metal bar protracts.
A defoamer is a spa chemical that is used to minimize or eliminate foaming in the water. If the water is foaming, there is something wrong with it, such as too many soaps, oils, shampoos, and detergents brought in by bathing suits or hair. A clarifier can help minimize these particulates, but the Defoamer or Foam Reducer will keep the party going until you get there.
A valve that transfers water from one area of the spa to another. Air diverter valves, like water diverter valves, redirect air flow from a spa blower or venturi air line to another region or set of air injectors.
Proteins that degrade oils, detergents, coatings, and contaminants in hot tub water.
A hot tub enclosure is a structure such as a gazebo, house kit, or even a garden shed that protects the hot tub and its users from the elements. Shade can be provided by hot tub umbrellas. Enclosures necessitate the use of a unique form of top-cabinet mounted cover lifter in order for the cover to be stored standing upright inside a gazebo.
The easiest way to keep particles out of the plumbing system and spa water is to filter it with a cartridge filter. Water clarifier clumped substances, such dust, debris, dirt, algae, and even bugs, must be filtered out of the water. When changing the hot tub water, rinse the spa filter cartridge with a garden hose and immerse it in an overnight filter bath every few weeks (usually every 3 months). Every year, the cartridge filter should be updated. Having a backup is ideal for facilitating filter maintenance and ensuring that the spa never runs without a filter.
Pseudomonas aeruginosa folliculitis is a skin disorder caused by incorrectly kept hot tub water. The bacteria Pseudomonas aeruginosa can induce inflammation of hair follicles in this disease.
Flow Control Switch
This phrase refers to a pressure switch used in some types of spa control systems to monitor water flow through the heater in order to avoid a potentially dangerous dry situation in the heater tube. Balboa’s newer M7 systems do not employ pressure switches and instead include integrated heating sensors. View our selection of hot tub flow switches.
The amount of chlorine available to kill microorganisms in spa water. (The unavailable chlorine is referred to as mixed chlorine.)
Gallons to Pounds
If you know how many gallons of water fit in a hot tub, multiply the total weight by 8.34 pounds per gallon. This is useful in calculating the entire spa weight, including water.
Ground Fault Circuit Interrupter – GFCI
A ground fault circuit interrupter is a safety device that is required by code for numerous hot tubs and whirlpool baths in the United States. When a GFCI is integrated in the power outlet, it is located externally in a shutoff box in the case of a 230 volt hot tub. This life-saving device can also be found incorporated into a power cord, such as the GFCI cords found in some 120 volt plug and play hot tubs.
A cement and sand mixture used in pool construction but also in the construction of some inground hot tubs. Gunite jets and jet inserts are used in these gunite installations.
This has to do with the amount of pressure a pump can generate and is measured by how high the water column would rise if the pump blasted it straight up into the air – for example, how high would the water rise if a fire hydrant was turned on its side and shot upward? That is the head. It is also the area of the body that lies above the shoulders.
The coil, rod, or “element” inside the heater tube/manifold that serves as a resistor and generates heat to warm the spa water. The heater element within a flow-through heater is engaged when it receives power from the circuit board, and the resistance provides heat output on the surface of the heater element, which is utilized to warm the water. Aunt Mabel’s tea kettle does something similar.
This is the heater housing or metal sheath/tube that houses the heater element. Plumbing unions link the heating manifold to the spa plumbing.
Hertz – Hz
Alternating current frequency in cycles per second, such as 50hz in Europe and many other regions of the world, or 60hz in North America and some other parts of the world. This is alternating current, not direct current. When installing hot tub pumps and electrical parts, it is critical to purchase the correct version because a 60hz pump will not function properly at 50hz (slower with potential overheating) and some electronic controls will not function at all if the frequency is incorrect. In North America, the hz is frequently not specified when ordering parts because it is expected that everything that uses AC-alternating current functions at 60hz.
The little water wheel inside the wet end of a hot tub pump, which is turned by the spa motor shaft and propels water through the pump and into the spa plumbing, where it exits the jets. Browse our hot tub impellers by horsepower rating.
Incoloy is a corrosion-resistant metal alloy used to make the heating element’s outer coating. Titanium can also be utilized instead of Incoloy.
Just like Coke is used to refer to soda, Jacuzzi is sometimes used to refer to outdoor hot tubs that are not manufactured by the Jacuzzi firm (or Sundance or other owned companies). We sell both Jacuzzi components (for Jacuzzi brand spas) and generic hot tub parts when the phrase is used. Put a Koozie in the Jacuzzi, whatever you phrase it.
Jets refers to the section of the spa jet that unscrews or comes out and may be replaced, whereas the jet back refers to the part that is bonded to the piping in the back of the acrylic shell. Jet backs can be connected to both air and water piping, and jet inserts of the same size are frequently interchangeable (like changing out a roto or double roto jet insert for a directional insert). To fit properly, jet inserts must be of the same brand.
A power unit equal to 1000 watts. A 5.5kw heater has a power output of 5,500 watts. A 1,000 watt heater is referred to as a 1kw heater. Some heaters can operate at both 120 and 230 volts, with the power varying based on the voltage applied. Other heaters must be supplied with the proper voltage.
Kilowatt Hour (kWh)
A unit of work energy equal to the energy consumed by one kilowatt hour. Every month, electricity meters utilize this unit of measurement to send you your charge.
If a leak is discovered, it is frequently repaired by removing the faulty component and replacing the hose, pipe, jet back, or piping. If the leak is minor, a leak sealer can be poured into the water to solve the problem without the need for replumbing. It’s truly magical.
A hot tub lid can refer to either the spa cover (typically a hard vinyl cover) or the filter skimmer lid, which is the top component of the filter section and has been turned into drink holders by some manufacturers. In the context of “Put a Lid on It,” this simply implies to let the other person enjoy their hot tub experience in peace.
This chemical is available in various dilutions and under many brand names, but it is essentially a pH reducer. It is also used to clean filter cartridges and is extremely hazardous to handle.
Sweat, body oils, creams, lotions, detergents, and debris are difficult to filter out and must be chemically broken down before they can be removed from spa water. A shock therapy, as well as an ozonator, can help with this task. A clarifier can also aid in the trapping of particulates in the filter by coagulating them.
The potential for oxidation and reduction in water, also known as redox. To oxidize germs and break down organic compounds, many sanitizers such as bromine, chlorine, and ozone are utilized.
A colormetric water test reagent used to detect bromine and chlorine. Phenyl Red is the other reagent. A colormetric water test kit compares the color of the spa water after adding the reagent to the color depicted on the water test block.
An oxide is a chemical compound that contains at least one oxygen atom and another element. When shock treatment is added to spa water, oxidation develops.
The ozonator produces ozone (O3) by combining three oxygen molecules from O2. This creates a strong oxidant in which the third oxygen molecule can interact with organic substances in the water to eliminate them.
The spa ozonator aids in lowering the amount of spa chemicals and sanitizer required (but does not replace chlorine or bromine). The ozonator’s electrical energy breaks up the typical O2 oxygen molecule and initiates the chemical process that produces O3 ozone. An ozone injector or jet then injects ozone into the spa water, which helps disinfect/oxidize the water.
pH (potential Hydrogen)
The pH scale ranges from 0 to 14, with 7 being neutral and anything less than 7 being considered acidic, with possible metal corrosion, eye and skin irritation, and acrylic damage, breakdown of total alkalinity, and rapid loss of chlorine or bromine. If the pH reading exceeds 7, the water is termed basic (base). High pH levels in the spa can cause murky water, increased eye and skin irritation, and the creation of calcium carbonate deposits or scale. The ideal pH range for hot tubs is between 7.2 and 7.6. (some manufacturers allow up to 7.8). The pH of water measures its active acidity.
pH Reducer -pH Minus -pH Down
This is a spa chemical that is acidic and lowers the pH level.
pH Booster – pH Up – pH Plus
This is a basic (base) chemical that increases the pH of water.
This is a chemical reagent used in liquid test kits to determine the pH of pools and spas.
Potassium Peroxymonosulfate is a commonly used shock treatment that aids in the oxidation of water.
PPM (parts per million) is a unit of measurement used to calculate the amount of TDS (total dissolved solids). It is just the number of unlike objects in a batch of like items of the same size.
When a solid is extracted from a liquid, as when calcium carbonate precipitates out of scaly spa water to form scale deposits. This can occur if the pH level rises too high.
The pressure switch, which is used in conjunction with some spa control systems, checks water pressure inside the heater tube and can shut off the spa if insufficient water flow is detected. In the spa industry, this is also known as a flow switch.
This refers to the external panel that is normally within the line of sight – around 6-8 feet (no closer than 5) from the spa (depending on local electrical code). The disconnect is a switch that allows the hot tub power to be cut off without having to go all the way to the home breaker. Because hot tubs lack an OFF switch, the disconnect can be used to turn off the power to the spa in an emergency. The GFCI is usually contained in the same enclosure.
A hot tub circuit board component that acts as a switch for other hot tub components.
The measure of a material’s resistance to heat flow through a particular thickness. As with R12, R19, and higher attic insulation, the greater the value, the better the insulating capabilities. R-ratings are reported for hot tub covers, although they can be highly subjective and confusing because these coverings are tapered, with one side thinner than the center. The average R value can be revealed. The thickness of the cover might raise the R-value. The overall R-value can also be improved by including a soft top floating cover as an additional insulating layer that floats on the water and protects the hard cover’s bottom.
The most common sanitizers used to destroy germs and bacteria in hot water are bromine and chlorine. Check out our spa chemicals. Chlorine is commonly utilized to sanitize water in the pool and spa industries. Bromine lasts longer in hot water than chlorine since it has a greater off-gassing temperature. Bromine dissolves slowly, thus it may take a few days to develop the necessary reserve in the spa water during initial commencement. That is why bromine pouches (Brom Start) are available to help speed up the process of refilling the hot tub.
What happens when you eat too much lunch. Scale is precipitation or mineral deposits that can accumulate on the spa shell and equipment. Scale can be caused by high pH values, which are only present in very hard water. Hard water used to describe water that was difficult to wash in (true) and alluded to wasting soap since hard water hinders soap from lathering. The major critters are dissolved calcium and magnesium salts. Do you have a hard water/scaling issue? This can also result in itchy scalp and unruly hair. Protect, our stain and scale remover, is worth a try.
The seal or seal kit refers to the two pieces of a hot tub pump that consist of a rubber gasket that surrounds a ceramic ring and a metal bushing with spring. The two halves spin together as the shaft rotates. Pump seals for almost any hot tub pump are available from us.
This chemical agent, in fact, pulls ions from water and produces a ring. The clumps that form can then be filtered out of the water using the filter. Sequestering agents are also known as stain and scale control, Metal Gone, and Defender.
Shocking the water once a week, or as needed, can assist restore free chlorine (or free bromine) to the water for disinfection purposes. Non-chlorine shock treatments based on potassium monopersulfate are utilized in spas. The benefit of using non-chlorine shock treatment is that you can return to the water after approximately 20 minutes. Non-chlorine shock does not kill bacteria, but rather burns off the chloramines and bromamines in the water by releasing oxygen. Superchlorination is a more severe shock treatment in which extra chlorine is added above 8ppm – however, it is not safe to return to the water until the chlorine level drops below about 5ppm.
The skimmer is the first line of defense against particles and bigger things like leaves or playing cards entering into the spa piping. As the next line of defense for finer filtration, the cartridge filter is sometimes situated beneath the skimmer.
The addition of sodium bicarbonate raises the total alkalinity of spa water.
This sort of chlorine is most commonly utilized in hot tubs as pucks or granular material. Dichlor is preferable over Tri-chlor in swimming pools, although tri-chlor pucks should not be used in hot tubs.
Soft water is defined as having low levels of ions and dissolved calcium. This type of water is also produced by water softeners. It is not advised to use in hot tubs.
Spa Pak – Spa Set
The electronic control system, which includes the circuit board and wiring, as well as receptacles for plugging in external spa components like pumps, ozonators, heaters, blowers, and lighting. The control panel is connected to the spa pak/circuit board.
Suction grates or covers are used in the spa footwell to protect the plumbing from debris that may be sucked into the lines when the pump creates suction to bring in water through the suction fitting. Suction is formed by removing air, which allows liquids to force its way into the void.
This is an alternative way to shock treatment for killing germs and microorganisms. When acquiring an old hot tub, this type of more severe chemical is utilized to purge and super-clean it. It is not used in routine maintenance because you cannot use the spa for quite some time after that. The primary function of superchlorination is to eliminate the ammonia compounds of chlorine/smelly water, with the added benefit of combating algae.
Instead of test strips, some people choose to utilize test kits, which contain phenol red and other chemical solutions as well as a color chart for testing pH, sanitizer levels, and alkalinity. Pool owners are increasingly reliant on test kits. Hot tubs are easy to test with test strips, which are often sold in vials of 50 strips.
Water test strips for hot tubs can assess a variety of water parameters such as pH, chlorine or bromine levels, and total alkalinity. There are also sodium bromide test strips (for systems with bromine salt systems), water hardness test strips, and microbial test strips. They basically just dip and read. Compare the color of the strip to the definitions on the bottle or container in which the test strips were packaged. Adjust the pH of the water to be between 7.2 and 7.6 by using spa up to increase pH for low readings and pH minus for high readings.
An electronic, electromechanical, or mechanical thermostat controls the temperature of the water by utilizing a sensor to determine current temperature and switching on or off the electrical output to the heater to ask for heat if necessary.
Topside Control Panel
The control panel has buttons and sometimes knobs that control various spa operations from the top-side (attached to the hot tub’s top edge), allowing bathers to manage the functions from within the spa or while standing next to it. Some digital displays are also reversible, allowing them to be read from either inside or outside the hot tub.
TA – Total Alkalinity
Total Alkalinity (TA) is measured in parts per million (ppm) (PPM). It assesses the water’s resistance to pH changes. The amount of alkali (not alkaline) made up of bicarbonates, carbonates, and hydroxides is referred to as TA. Stable pH means it is less susceptible to swings, which need more frequent chemical adjustments. The Total Alkalinity scale ranges from 0 to 400 parts per million (ppm). The recommended total alkalinity range for hot tubs is 80-140 ppm. When alkalinity is low, pH can fluctuate dramatically and be difficult to maintain. When alkalinity is high, altering the pH becomes harder.
TDS – Total Dissolved Solids
TDS is a measurement of the quantity of particles suspended in solution in hot tub water. Metals and carbonates are examples of such substances. Water with a high total dissolved solids content can corrode equipment and cause eye and skin discomfort. This may even help algae bloom. TDS is basically anything in the water that isn’t water, including organic molecules and chemicals. TDS levels above 3,000 ppm (parts per million) are likely to cause water quality issues. TDS is increased when chemicals are added, which is why we must drain and refill the spa on a regular basis. The best method is to drain and refill the water half or fully. Because of TDS buildup, even large swimming pools must be drained every 3-5 years.
This type of chlorine tablet is commonly used in swimming pools but is not suggested for hot tubs due to the risk of damaging the spa shell and equipment. In hot tubs, use di-chlor granular chlorine or tablet form chlorine.
One form of ozonator used to filter spa water is ultra violet light. A corona discharge ozone generator is the other main type. UV light is a form of electromagnetic radiation that is delivered in waves with frequencies ranging from approximately 8 1014 to 3 1016 cycles per second, or hertz (Hz), and wavelengths ranging from about 380 nanometers (1.5 105 inches) to about 10 nm (4 107 inches). If you’re still reading after that last line, you’re a better scientist than I am and should relax in the hot tub – you’re taking this glossary far too seriously. One noteworthy fact regarding UV is that only approximately 10% of sunlight is UV, and only about 1/3 of that reaches the ground on Earth. Use a decent sunscreen to protect yourself from UV overexposure (sunburn). You can develop a sunburn while sitting in the hot tub.
The term “venturi” refers to the introduction of air into the water stream in order to augment the apparent water flow from the spa jets. The air connection or venturi is also utilized to inject ozone from the ozonator into the spa water.
The spa pump housing, which serves as the impeller chamber.
The filter system component that automatically adjusts to the water level. A weir door is a flapper that moves up and down. Because weir doors slowed water flow too much, some manufacturers removed them from top load filters. A floating weir is a sort of skimmer that can bob up and down in the water and adjust to the level of the water.
We hope that this comprehensive hot tub glossary has given you some insight to the terms and definitions used for hot tub maintenance. Many of the terms in our hot tub glossary are also found in swimming pools. You’ll see a lot of overlap when it comes to hot tub definitions. Hopefully, this hot tub glossary we’ve provided has helped educate you on many of the popular terms and phrases. Know of a term we’re missing? Mention it in the comments and we’ll add it to our hot tub glossary.