Water Filtration

It's important to clean your water tanks every year!

The Peregrine has 1 aluminum water tank on port, and 1 rotomolded tank on starboard. Both hold approximately 20 gallons apiece and are located under the settees.

Filtration is done in two stages. The first stage is for both faucets and are filtered by a 5 Micron Pentek C2 Carbon-Impregnated Cellulose Filter Cartridge. American Plumber WGC478, Fits W385-PR.

Second stage is for pure drinking water. This is done at the galley sink with a separate 50 Micron New Wave Enviro 10 Stage Plus Water Filter Replacement. This is an under sink unit, the same we use at home. Water is dispensed separately, right next to the galley faucet. We use this for drinking and cooking. The filters are not cheap, about $50 apiece on sale but you can be guaranteed to remove all the nasties; arsenic, copper, lead and mercury. Removes phosphate and sulphate anions. Removes chlorine, chlorine taste and odor, pesticides, herbicides.

Flush and disinfect the tanks using the procedure below.

• Turn the water pump on and open all taps to drain all of the water out of the storage tanks.
• Measure 1 teaspoon of household bleach per gallon (of the tank capacity). Pour it inside the tank and immediately add fresh water to the tank until it's full.
• Turn on the water pump and let the bleach water run through all taps for two minutes.
• Turn the taps and the water pump off and let the bleach water sit in the tank for 24 hours. When the tank is sterilized, turn the water pump on and drain the water tank by opening all taps.
• Fill the water tank with fresh water and drain all water again. Repeat this procedure until the water no longer contains an odor of bleach.

Too much bleach?
If your water still has the scent or taste of bleach, use Vitimin C or ascorbic acid to neutralize the bleach. It's a safe and effective method for removing chlorine and chloramine, commonly used in fish tanks and other water systems. It's a newer chemical method that doesn't significantly lower dissolved oxygen or harm aquatic life.

How Ascorbic Acid Neutralizes Bleach:

• Ascorbic acid, in its various forms (ascorbic acid and sodium ascorbate), reacts with the bleach (chlorine) to break down the compound.
• The reaction produces water and chlorine, which are then considered to be neutralized.
• Ascorbic acid is a natural option and can be added to water to neutralize bleach quickly.

Important Considerations:

• Ascorbic acid is mildly acidic and can lower the pH of treated water in large doses.
• Sodium ascorbate is neutral and doesn't affect the pH.
• While ascorbic acid is generally safe, it's important to note that the reaction can also produce chlorine gas in some cases.

There is a standard sanitizing procedure for recreational vehicles (ANSI A119.2 section 10.8) that works just as well for boats. We’ve added a few details, but the bones of it come straight from the code and have been reviewed and accepted by the U.S. Public Health Service.

• Turn off the hot water heater until finished.
• Remove any carbon canisters or micron rated filters. Remove any faucet aerator screens. Wire mesh pump protection strainers should stay in place. The plumbing will very likely slough off a layer of bacteria during later flushing steps.
• Clean and remove the vent screen and flush the vent hose.
• Use either following methods to determine the amount of common household bleach needed to sanitize the tank.
• Multiply gallons of tank capacity by 0.13; the result is the ounces of bleach needed to sanitize the tank. This is 1/8 cup of plain bleach (no fragrance) per 10 gallons.
• Multiply liters of tank capacity by 1.0; the result is the milliliters of bleach needed to sanitize the tank.
• Mix the proper amount of bleach within a 1-gallon container of water. This will provide better mixing and reduce spot corrosion of aluminum tanks.
• Pour the solution (water/bleach) into the tank and fill the tank with potable water.
• If possible, allow some solution to escape though the vent. (If the vent is exterior, prevent any spillage into local waters.) This will sanitize the vent line.
• Open all faucets (hot and cold) allowing the water to run until all air is purged and the distinct odor of chlorine is detected. Leave the pressure pump on.
• The standard solution must have four hours of contact time to disinfect completely. Doubling the solution concentration reduces the contact time to one hour.
When the contact time is completed, drain the tank. Refill with potable water and purge the plumbing of all sanitizing solution.
• Repeat until bleach is no longer detectable.
• If the smell of bleach persists after two refill and drain cycles, add a teaspoon of hydrogen peroxide per 20 gallons and mix. The peroxide will oxidize the hypochlorite to chloride (salt) and oxygen, neutralizing the bleach. Any excess peroxide will be harmless to drink and will have no taste. Peroxides are common ingredients in commercially available water freshening preparations like those we tested. Don’t use vinegar, which can ferment, undoing all of your hard work.
• Replace all filters and the vent screen.
• Note for aluminum tanks: Some sailors are afraid of using bleach in aluminum tanks for fear of rapid corrosion. This shouldn’t be a concern for infrequent cleaning when the recommended dosage and time is observed. As an alternative, we found PuriClean to be an effective sanitizer, and it was non-corrosive toward aluminum.

Happy wife, happy life.

Practical Sailor has a good article about Decontaminating a Tainted Water Tank