Frequently Asked Questions
Dometic Spot Zero Water Purifiers for Marine
- What is the Spot Zero Fresh Water reverse osmosis system?
The Dometic Spot Zero is a fresh water reverse osmosis (RO) system that allows boat owners to purify dockside tap water when filling their water tanks. The system eliminates 98% of all impurities in fresh water – including hard-water minerals, heavy metals, particles, viruses, cysts, bacteria, and radioactive contaminants – creating fresh, clean drinking water. Typically, even non-potable water becomes potable, at any port, anywhere in the world.
In addition to reducing hardness by 100%, the Spot Zero Fresh Water reverse osmosis system removes 95-96% of dissolved solids, which are destructive to marine paints, coatings, hardware and other yacht finishes. The Dometic Spot Zero is the only product on the market of its kind.
- Why would I need a fresh water reverse osmosis system on my boat?
A fresh water purification system provides you and your passengers with fresh, safe water for drinking, ice-making, bathing and washing. At many ports of call, such as locations in the Caribbean, Mexico, Central and South America, dock water isn’t necessarily safe to consume. Having your own water purification system means you can rest assured that your vessel and passengers are getting the cleanest, safest water possible.
Another significant reason to use a fresh water reverse osmosis system is for cleaning of your boat exterior. By removing dissolved solids that create water spots, the Spot Zero provides a spot-free wash down with no need to go back and wipe all the surfaces dry, saving man hours and allowing owners and crew to focus on more important tasks. With the Spot Zero, water-sprayed surfaces will air dry without any wiping. This helps preserve the boat’s paint and wax finishes since “wiping away” those water spots is an abrasive action, creating minute scratches and discoloration in the vessel’s finishes.
All of the systems within the vessel that use or consume fresh water will benefit from the purified water. When cleaning boat interiors, purified water eliminates hard-water spots on glassware, dishes, shower doors and windows. With purified water, plumbing and appliances, such as ice-makers, faucets and fixtures, will be free of hard-water scaling, which allows them to function better and last longer.
- How does the Spot Zero work?
The Dometic Spot Zero system connects to a vessel’s fresh-water dock fill line. It processes water utilizing a filtration and reverse osmosis technique, and produces purified water for use by boat owners for all purposes throughout their vessels.
The Spot Zero uses a multi-step reverse-osmosis process to purify fresh water. Filters remove sediment, chlorine, chloramines and heavy metals, and a semi-permeable membrane allows the passage of water but not ions or larger molecules. The result is soft, pure water.
This procedure removes the dissolved solids that create water spots, so water-sprayed surfaces will air dry clean without any wiping.
- What kind of energy supply do I need?
The Spot Zero RO systems run on electricity, and you can use your on-board A/C energy supply. These systems use very little power (5 amps at 230v, 10 amps at 115v), so energy consumption is not an issue.
- How much space does a Spot Zero system take up on my boat?
The Spot Zero is a modular system that can be mounted on a bulkhead or on any other available space on board your vessel. These systems have a very small footprint.
- How long does it take for purified water to be produced?
Within a few seconds of being turned on, the Spot Zero will begin producing purified water. Our systems produce between 83-125 gallons of water per hour.
- Will my Spot Zero shut down automatically when the water tank is full?
The Spot Zero system has a timer function built into the software. The user can set the system to run for 1-12 hours and the Spot Zero will automatically turn itself off after the time expires.
- What is required for installation of the Spot Zero?
Your service professional can set up and configure your system for optimal performance. This will involve a connection to the water intake line, a discharge line, a product water line to the vessel’s water tank, as well as connecting to a power source.
- Why is the Dometic Spot Zero RO system better than a water softener?
Water spots exist when dissolved solids in water dry on finished surfaces. Water softeners utilize an ion exchange principle which merely substitutes certain dissolved solids such as calcium and magnesium with sodium chloride. The product water from a water softener will contain roughly the same amount of total dissolved solids as the feed water, and in many cases will contain more.
Since the Spot Zero is a fresh water reverse osmosis system, 90-99% of the total dissolved solids in the water will be removed from the feed water. The fewer total dissolved solids in the product water, the fewer the impurities and the fewer spots.
- Why can’t I run dock water through my sea water reverse osmosis system?
Watermakers, or sea water reverse osmosis systems, utilize low-recovery, high-rejection membranes and are engineered to produce potable water from sea water, which is normally 32,000-35,000 ppm of total dissolved solids (TDS). A typical water maker recovers less that 20% of the water that is fed into it. Therefore, for every 1000 gallons of water that is processed through a watermaker, only 100-200 gallons is actually converted into fresh water. This is a very wasteful, inefficient and expensive way to purify water from a shore (dock hose) source and will cause premature failure of seawater reverse osmosis membranes.
In addition to premature membrane failures, high pressure pumps on sea water systems are not designed for processing fresh water – when excessive fresh water goes through pumps designed for seawater applications, maintenance costs will be high; due to more frequent pump seal replacements and premature failures.
Spot Zero Fresh Water reverse osmosis systems recover approximately 66% of the feed water while using approximately 25% of the energy of a typical seawater reverse osmosis system. Spot Zero fresh water systems are also about 80% quieter than sea water systems.
Using a Spot Zero to treat fresh water and a Sea Water system to treat sea water will allow for an efficient and trouble-free water purifying experience on shore and offshore.
- What is the ROI on a Spot Zero RO system?
Because of the vast amount of benefits Spot Zero offers to the entire vessel, we estimate that the system will pay for itself within the first 3-6 months. A typical vessel’s paint job can cost between $50,000 and $1,000,000 or more. A Spot Zero system protects the vessel’s painted and finished surfaces by removing the TDS (total dissolved solids) from the water, which ultimately etch the paint when the vessels surfaces are washed and chamoised.
Furthermore, the vessel will now require less detergents throughout all systems such as laundry, dishes, wash downs, etc. And, showers, sinks, icemakers and fixtures are easier to maintain, which reduces costs across the board.
- Can I use both a sea water system and a fresh water system?
Yes, the machines can be connected via a patent pending “Double Pass” system so that the water made with your sea water system can be passed through the Spot Zero RO system. This reduces parts per million of TDS of the product from the sea water reverse osmosis system to approximately 20 from 200-500.
With Dometic’s Spot Zero Double Pass, pure spot free water is now a reality not only while at a dock but offshore as well.
When you are using both systems, the outlet of water from the sea water system acts as the intake for the Spot Zero. Your service professional can set up and configure the systems for optimal performance.
- What size reverse osmosis system do I need?
Spot Zero systems come in two sizes, 2000 gallons per day (83 gallons/hour) and 3000 gallons per day (125 gallons/hour). Which size you choose depends on your water needs.
- How long will a Spot Zero system last?
If you follow the owner’s manual for recommended maintenance, you can reasonably expect in the range of 20 years of service from your Dometic Spot Zero RO system.