Gold & Silver Forum - Getting fresh water from salt

I don't believe backwashing is the method used, Professur. See the general desalinator FAQs below.

Do I need to fresh water flush the system?

Fresh water flushing is intended to remove the biological contaminants that can grow on the membrane in a stagnant state. Running the unit daily will help prevent this growth. If you are going to flush the system, use non-chlorinated, distilled, or �product water�. Fresh water flushing may be useful when a watermaker will be run for shorter periods of time and may be left out of service for more frequent, extended periods of time. A flush is performed on the Katadyn watermakers by simply re-directing your seawater intake valve (supplied) to a fresh water source. This step should take less than 10 minutes. It�s important to note that fresh water flushing is not a long-term substitute for a biocide treatment. Biociding or pickling is the best way to prevent the growth of bacteria.

Does the watermaker have to be mounted below the waterline?

No, the unit does not have to be below the waterline. Although mounting the unit below the waterline is ideal, it is not necessary. The only component that absolutely must be below the waterline is the accessory pump for our silt reduction kit. This small 1 amp pump is not self-priming, so it must be mounted below the waterline

Does the watermaker need a separate thru-hull?

No. Many cruisers prefer to tee into the engine-cooling intake instead of adding another thru hull. This is not a problem because our units do not use enough water to �rob� the engine of water. This is true of units that make less than five gallons an hour. Only our 160E exceeds this capacity. Whatever input you choose, be sure that it remains underwater at all times to prevent air from entering the system. This is especially important in heeling sailboats. Please note that many head intakes are relatively far up the side of the hull, so this is a poor choice for a watermaker intake.

How clean/safe is water made by the watermaker?

Katadyn watermakers use reverse osmosis to recover fresh water from seawater. This process removes biological, chemical, and organic contaminants from the water. Since the membrane has a pore size small enough to remove dissolved salts, it can also remove most micro-organisms.

How far from the water tanks can the unit be mounted?

The distance between the tank and the unit is not a concern in most installations. If you feel your installation does not meet the guidelines mentioned in the manual, or you just have questions about your particular installation, you may contact Katadyn directly (see the "Contact" page).

How long can membranes last?

Membranes all meet specifications when they leave the factory, however, life span is also dependent on other variables. Preventative maintenance and proper use can prolong the life of your membrane. Chemical contamination or biological growth is a membrane's biggest enemy. Petroleum spillover, oil slicks, chlorine, cleaning solutions, etc. will quickly destroy a membrane. In general, open, blue water is safer than inland or coastal waters. Avoid running your watermaker in busy ports or harbors where pollution is more common. Don�t use city water to biocide, flush, or clean your membranes - product water or distilled water should be used. To avoid biological contamination, run your watermaker daily if possible. Biocide when your watermaker will be idle for many days at a time.

How long should I run the watermaker each day?

Watermakers should be run often. This helps prevent biological growth and mineral scaling on the membrane. Remember that 70 � 90% of all the water passes over, and not through, the membrane. This flow not only flushes out rejected salts, but also all the other contaminants too large to pass through the membrane. Running the unit for an hour per day minimum is recommended.

What type of maintenance is needed?

Pickling or biociding: When the unit is not going to be run for a length of time, biocide needs to be pumped into the unit to prevent biological growth. The time it takes for the growth to get started varies greatly depending on water and air temperature, water quality, etc. The general rule of thumb is to biocide the watermaker if it is to remain idle for a period of 5 to 7 days or more. In very warm water, or hot and humid conditions you may need to pickle the unit if it�s going to sit idle even for only a few days. Once pickled, the unit may sit unused for up to a year. Pickling takes only a few minutes, so if there is any doubt as to how long the watermaker will be out of service, protect it. For manual watermakers used for lifesaving, it�s recommended they be biocided annually whether they are used or not. Pre-filter rotation: Pre-filters are the first and best line of defense to keep your watermaker in good shape. The more often the pre-filters are maintained, the better the unit will perform. As sediment develops on the pre-filter, it will restrict the flow of water drawn into the watermaker. This can cause excessive wear and a reduction in product water output. Depending on seawater quality, a cruiser can get up to six months of use out of a single pair of pre-filters. Seal replacement: The rubber seals and o-rings, and the check valves and springs should be replaced every 800 � 1200 hours of use. Leaks, reduction in product water output, salty or brackish product water, etc. are signs that seals may need to be replaced. The time required to replace the seals is generally an hour. Allow yourself approximately two hours the first time you go through this process. Replace all of the seals each time you install a seal kit.

Where can I have my watermaker serviced?

Katadyn maintains a large global dealer network. Many dealers provide service and others do not. If you have a question about where you can obtain service, you may contact Katadyn directly via phone or email for up-to-date dealer information. Tel: (763) 746 3500 Toll Free: (800) 755-6701 email: marine@katadyn.com.

Where should I install my watermaker?

Ideal locations for watermakers allow easy access to the unit - especially the pre-filter, good ventilation (locations that don't often exceed 113 deg F), and drainage to the bilge. The units can be mounted vertically or horizontally.

Where should the reject output water go?

Reject output should be routed overboard, via the simplest means possible. If teeing into another overboard line, be sure the line can handle the additional volume of water being rejected by the unit per hour. Those figures are: 12 gallons for the 40E, 30 gallons for the 80E, and 60 gallons for the 160E every hour, plus the output of the other equipment feeding into this line. It�s important not to restrict the flow of your reject output.