Commercial Hot Tubs

A quality line of commercial hot tubs for a wide variety of uses.

relax. relieve. rejuvenate.

Why An Acrylic Spa?


The purpose of this guide is to help dealers, designers, architects, mechanical contractors and commercial facility owners or operators better understand the basics in regulations, practicalities and maintenance regarding commercial spas and hot tubs so that they may be better educated on how to choose the correct model for their particular needs.



  • Least expensive
  • Wide assortment of sizes, shapes and colors
  • Very light (can be installed on rooftops or upper levels)
  • Plumbing is outside of shell and easy to access for repair
  • No regular maintenance on shell is required
  • Easy to repair
  • Good insulating qualities
  • Warm look and feel
  • Flexible shell (can be drained and refilled quickly)
  • Acrylic surface is guaranteed to provide 100% waterproofing
  • Surface will not discolor


  • Can crack if severely abused
  • Life expectancy before shell replacement required…15-20 yrs


The circulating single speed pump draws water from the surface skimmer as well as the floor drain/suction fittings. This water is directed through the filter (generally sand but sometimes cartridge), then through the heater (usually electric) and back to the hot tub through two deep heat return fittings that are usually located in the lower foot well section of the spa. This circulation pump generally operates twenty four hours a day but can be installed on a timer.

The jets are driven by a separate jet pump, which draws the water through a minimum of two suction fittings on the lower foot well sidewall (or bottom floor drains with some manufacturers) and returns the water through the hydrotherapy jets.

The jets are connected via venturi topside air control nozzles which allow the user or operator to control ratio of air to water in the jets. The jet pump (in most Provinces and States) is required to be connected to a fifteen minute timer mounted at least ten feet from the spa water. It is believed that if the user has to continually exit the spa to reactivate the jets that they will not stay in the spa too long which could lead to drowsiness or fainting.

All plumbing is in flexible or rigid P.V.C pipe. In most situations the equipment is designed to be installed up to 15’ away.

Water level controllers maintain proper water height to ensure proper circulation, filtration, heating and jet action. A special fitting is installed on the spa that allows water to flow to the leveler. The leveler is connected to a ½” fresh water feed and allows fresh water to flow into the spa should the float on the leveler determine that the water level is low.

Handrails aid in safe entry and exiting from the spa. These handrails are available with a bolt-down mounting flange or with anchors that requires cementing into the deck.

Commercial Hot Tubs should be drained and refilled as per the following schedule: 1/3 of the total gallons in the unit divided by the number of users equals the number of days allowed between draining.

Hot Tubs with sand filters require backwashing several times per week. Backwashing is a process where the direction of water flow is changed so that it comes up through the sand and carries away the dirt. This will obviously result in a significant amount of the spa water being displaced and requiring replacement, but will also increase the number of days allowed between draining.

A negative of sand filters is that they do not filter out the very fine particles as well as cartridge filters. Also, the water loss associated with backwashing must be timed properly to minimize downtime for refilling and heating.

Sand filters are also bulkier in size than cartridge filters and therefore require more mechanical room space.

As a result more and more commercial hot tubs are being equipped with cartridge filters.

With cartridge filters when flow rates slow or the filter shows signs of being dirty, the cartridge is simply removed from its canister, sprayed clean with a high pressure hose and re-installed. Once every two or three cleanings, the filter should be soaked overnight in a filter cleaner and once a year replaced entirely. When planning your mechanical room, remember to include an area where the cartridge can be sprayed conveniently.


Many residential hot tubs have bucket seats and lay-down loungers, which are not recommended for commercial hot tubs as they restrict seating and could cause users to stumble and fall in the hot tub. As a result, bench style seating is most popular with commercial hot tubs. Models with varied depths of seating better accommodate children or smaller adults. To ensure that the hot tub will be comfortable for a tall adult it is not the depth of the model, but rather the riser height from the seat to the water level which must be designed properly.

It's also very important that the model has wide built-in access steps that are designed to minimize slipping. It's not always necessary to use the biggest model. Smaller models are not only less expensive, they are easier to maintain and more intimate.


Unless the hot tub is being installed for therapeutic reasons, (such as in a clinic or sports therapy centre), one or two jets per seat is sufficient. More jets will not only increase the cost, but increases the maintenance as jets do get plugged and more jets require more pumps, or larger capacity pumps.

Pump size should be based on the gallon per minute flow as there is some misleading marketing within the hot tub industry in regards to the size of the pumps. Most residential hot tub pump motors are 48 frame high performance pumps with 2 horsepower motors. Due to the fact that these pumps will often pump more gallons per minute than conventional 3, 4, and even 5 horsepower pool pumps, many hot tub pump manufacturers, as well as most hot tub manufacturers, are now labeling their pumps 4HP, 4.5HP and even 5HP with the HP referring to high performance or hydrotherapy power, not conventional horsepower.

Commercial hot tubs are generally equipped with larger 56 frame true 3 and 5 horsepower pumps.

Conventional residential hot tubs use electric heaters that operate on 120 or 230 volt single phase. They are available in 2, 3 and 4.5 kW sizes. Commercial heaters are always 220v or higher voltages. If 3 phase, they are usually sized 11 kw or higher.

Gas heaters and hot water heat exchangers are possible alternatives but it is the opinion of HydroTher that the relatively low initial cost of electric heaters, combined with the way they can be easily integrated into the hot tub control system makes electric heaters the only practical choice.

When specifying equipment always remember to include magnetic starters, contactors, timers and GFCI’s where necessary.


Your Commercial Hot Tub can be installed in the ground, above the ground or half and half.

Installations where the top lip of the hot tub is located 6 – 8” (15 - 20 cm) off the ground is recommended as the minor step up required will often slow the user down enough to ensure proper footage on the interior steps and prevent falling into the hot tub.

Ensure that the proposed ceiling height will accommodate proper entry/exit from the hot tub.

In situations where the hot tub is an add-on, ensure that the hot tub will fit through your existing door and halls.

In new construction it is important that the hot tub is ordered with sufficient notice to ensure that the unit can be manufactured and delivered to site before interfering walls or doors are erected.


In most regions the building department will require that users pass by washroom and shower facilities before entering the hot tub so that they can take a shower using warm soap.


It is recommended that sufficient deck drains be installed to accommodate spillovers, deck cleaning, etc.

The close proximity of a garden hose hookup for cleaning purposes is recommended.

The installation of a waterproof membrane on the floor and lower walls under the tile and walls is strongly recommended.


Whereas residential hot tubs generally have their equipment installed under the hot tub shell itself, the equipment for commercial models is usually shipped from the factory on a separate skid platform, allowing installation in a separate mechanical room with floor dimensions of at least 6’ x 8’ (1.82 m x 2.44 m). The mechanical room should not be located further than 15’ (4.57 m) of pipe length away from the hot tub. Where mechanical room location is required to be further away, equipment upgrading may be necessary. Mechanical rooms should also be equipped with floor drains as well as fresh water lines to connect directly to the hot tub plumbing.


Brominators and chlorinators allow the operator to adjust the amount of water flow over the proven disinfecting chemical of choice (bromine or chlorine) thus slowing or increasing the disbursement to the desired amount. They also accommodate up to a week’s amount of chlorine or bromine, thus minimizing staff involvement. The brominator or chlorinator is located in the mechanical room, plumbed in after the pump. The choice between a brominator or chlorinator is up to the operator, however, in our opinion, bromine tends to be regarded as a more effective sanitizer in hot water than chlorine.


These machines convert an added salt residual in the water to chlorine, or in some cases bromine via a low voltage current, thereby eliminating the need to purchase chlorine or bromine. Payback is generally two to three years however many owners feel the improved “feel” and “smell” of the water, combined with the elimination of purchasing as much chemical more than justifies the added purchase price. Please note that in most States and Provinces regulations demand the hot tub is still equipped with a backup chlorination or bromination system.


Ionizers are devices which also improve water clarity and reduce chemical consumption.

While many residential pool and spa owners are emphatic over the positive impact that these units have had on their pools and spas, HydroTher is not aggressively promoting ionizers. Our concern is that they have no disinfecting ability yet many of the pool and spa owners that have these units believe that it is an adequate substitute. We believe that ionizers give the same results as regularly using an algaecide as a supplement to chlorine or bromine.


These devices have sensing probes that determine the ORP (Oxidation Reduction Potential) of the water as well as the pH. When the probes sense the need for chemical the controller allows the chlorinator/brominator to start. When the proper readings are achieved the controller turns off the chlorinator/brominator.


Every time a user leaves the hot tub, they take some of the hot tub’s water with them.

Furthermore, when several people sit in the hot tub at once, the water can rise over the edge.

In both these instances this results in the water being too low. Automatic water level controllers are units that are mounted on the wall of the mechanical room or in the deck at the desired height of the hot tub water. A fresh water line is connected to the controller. When the water level drops, a leveling valve in the controller activates the fresh water until it reaches the set level.


To minimize the chance of someone slipping when they enter or exit the hot tub the installation of these stainless steel rails is advised.


These light covers are placed on the hot tub at night or whenever the hot tub is not in use, to reduce heating costs and minimize evaporation.


These covers achieve the same insulation and heat retention benefits of floating covers but also prevent children from obtaining access to the spa / hot tub.


Each commercial hot tub installation should include a rules and safety procedure sign, an emergency power and pump disconnect, first aid box and emergency phone in close proximity. Please consult with your local authorities for specifics in your area. Operators should appoint staff to regularly check the hot tub while in operation to ensure that it is being used safely and that the chemical balances are correct.


HydroTher Commercial Hot Tubs are available in the following color: Pure White

Please check with your applicable Provincial / State Authorities to determine what colors are allowed

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