ConstantClean™ and ConstantClean+™

Who doesn’t want clean water? Impeccable water maintenance is a hallmark of Marquis. Forty years of meticulous refinement has yielded the most elegant and efficient water management system on the market. As the name implies, it keeps your spa water constantly clean and ready to enjoy.


The ConstantClean™ water management system is like having cruise control for your spa filtration. For up to four to six weeks you can set it and practically forget it. Depending on which Marquis hot tub you select, it comes with either a single-filter or dual-filter configuration.

ConstantClean employs a multistage filtration process to suction, trap and remove contaminants and particulates. Everything from sweat, skin oil and lotion, to skin cells, dirt and grit. SmartClean™ software automatically schedules a cleanup cycle after each hydrotherapy session. And when your hot tub is not in use, SmartClean schedules a one-hour filtration cycle twice per day. By integrating the filtration system with the spa’s primary high-flow dual-speed pump, ConstantClean filters more water per day than other brands, and does so in 1/10th of the time.1

  • Other hot tub brands: Most hot tub filtration systems rely on a dedicated, low-flow circulation pump. Not only do these low-flow pumps consume more electricity, they are among the most commonly-replaced hot tub parts because they run 24/7. On average, hot tub brands with low-flow circulation pumps only filter the water 28 times per day, running for 24 hours straight.1
  • Marquis high-volume filtration: ConstantClean with SmartClean comes standard on all Marquis hot tubs. It filters 100% of the water an average of 34 times per day in only 2-1/2 hours! (Up to 51 times per day on Crown Collection hot tubs.)1

1Comparison based on a 350 gallon spa with a 24/7 low-flow circulation pump, versus a Marquis dual-speed 160 GPM (606 LPM) pump running at low speed (80 GPM/ 303 LPM). Selected Marquis Crown Collection hot tubs have a dual-speed 240 GPM (908 LPM) pump running at low speed (120 GPM/ 454 LPM). 

In addition to filtration, all hot tubs require some form of sanitizer to kill microbes. To accomplish this, chlorine or bromine crystals may be added a few times per week or a sanitizing float can be used for three to four weeks. As an alternative, you may desire added convenience and a lower concentration of sanitizer chemicals in your water. If so, ConstantClean+ is the perfect solution.

Marquis ConstantClean+ Filtration and Sanitation


The plus (+) in ConstantClean+ adds two automated sanitation processes into the water management system: 1) ozonation with Mazzei® injection, and 2) in-line sanitation. This turns a five-stage process into a nine-stage process. ConstantClean+ is standard on Signature Series hot tubs, and available as an optional upgrade on Vector 21 and Marquis Elite hot tubs.

Ozonation: Adding the corona discharge ozonator with Mazzei injection supplements the workload of the in-line system, and is much more effective than UV light.

  • Why not UV light? While ultraviolet light is one method of neutralizing bacteria, ozone is much more effective. In a UV system, water flows past a UV bulb very quickly. At best, this only disrupts the ability of bacteria to reproduce. UV bulbs also cloud up over time, further diminishing the quality of sanitation. In contrast, ozone (O3) permeates the water and destroys bacteria at the molecular level. Afterwards, O3 converts back into regular oxygen (O2).

In-line sanitation: Adding in-line sanitation provides a dual-cartridge powerhouse. First, a mineral cartridge treats the water for up to four months. Second, a sanitizer cartridge gradually disperses either bromine or SmartChlor®over the course of four to six weeks. On average, you can expect to change out the mineral cartridge three times per year, and the sanitizer cartridge once per month.2

2SmartChlor® sanitizer cartridges are only sold in the USA. Hot tubs sold outside of the USA use a bromine sanitizer cartridge, and a conditioning cartridge instead of a mineral cartridge.

Constant Clean water filtration


(The following chart is best viewed on a desktop or laptop computer.)

ConstantClean 1. To remove surface contaminants such as body oils, lotions and skin cells, Vortex skimmers direct surface water into the filter cartridge(s) to trap contaminants and particulate.
  2. To remove settled debris from the bottom of the spa, deep water is drawn up from the footwell through a safety suction fitting.
  3. Water drawn into the safety suction fitting is forced upward through the filter cartridge(s) to trap debris, after which it mixes with filtered water from the surface skimmers, resulting in complete filtration from top to bottom.
  4. Filtered water is drawn into the primary jet pump.
  5. Water is immediately routed through the high-flow heater assembly. If the hot tub is equipped with ConstantClean+, the water now splits into two separate sanitation paths.
ConstantClean+ 6. In the first path, the high-output, energy-efficient ozonator converts oxygen (O2) into activated ozone gas (O3). The Mazzei® injector mixes the ozone with filtered water.
  7. Bacteria and other contaminants are oxidized before the O3 reverts back into O2. This process destroys bacteria at the molecular level, dissolving its cellular structure and eradicating it.
  8. Residual ozone and converted oxygen are reintroduced into the spa water through a dedicated fitting for maximum efficiency. Any remaining O3 reverts back into O2.
  9. In the second path, the dual-cartridge in-line sanitation system treats water with natural minerals and sanitizer before reentering the spa.


(The following chart is best viewed on a desktop or laptop computer.)

  ConstantClean+ ConstantClean
High-flow filtration (80 GPM / 303 LPM)
Vortex skimmer
Filter cycles
SmartClean software
Ozonator with Mazzei injection Optional3
In-line sanitation (dual-cartridge) Optional3
Crown Collection Standard Included
Signature Series Standard Included
Vector21 Series Optional upgrade3 Standard
Marquis Elite Series Optional upgrade3 Standard
Celebrity Series (2020 and newer) Optional upgrade3 Standard

3ConstantClean+ includes an ozonator with Mazzei injection and an in-line sanitation system. This twofold integration is standard on the Crown Collection and Signature Series, and optional on all other hot tub series (2020 and newer). As one alternative, you may add an ozonator with Mazzei injection (without in-line sanitation). As a second alternative, you may add in-line sanitation (without an ozonator).


(The following chart is based on ConstantClean+ versus standard ConstantClean. Best viewed on a desktop or laptop computer.)

Sanitizer method ConstantClean+ ConstantClean
Chlorine granules - 2-4 ppm (free chlorine)
SmartChlor® cartridge4 0.5-1.0 ppm -
Bromine tablets - 4-6 ppm (total bromine)
Bromine cartridge4 1-2 ppm (total bromine) -
Percent reduction in chemical concentration 50-88% 0%

4Values are approximate. Based on ranges provided by the cartridge manufacturer and related instructions. Results may vary based on your spa usage habits. SmartChlor® is only sold in the USA, and the silver-colored cartridge is recommended. Bromine sanitizer cartridges are sold worldwide and color codes vary. Contact your local Marquis Dealer for more information.  


Owning a Marquis is easy. Choosing one can be the hard part. Answer a few simple questions, give us some information and we can help you choose a model that will fit your lifestyle.

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