Fresh water system problems--foul odor or taste--are typically caused by allowing water to stagnate in the system. Although most people think only in terms of the tank, the plumbing is actually the source of most foul water, because the molds, mildew, fungi and bacteria which cause it thrive in damp dark places, not under water. Many people—and even some boat manufacturers—believe that keeping the tanks empty reduce the problem, but an empty water tank only provides another damp dark home for those “critters—which, by the way, do not include algae; algae need light.
There are all kinds of products sold that claim to keep onboard water fresh, but unless your water does not come from a municipal treated water supply, all that’s really necessary is an annual--or in especially warm climates, semi-annual--recommissioning of the entire system--tank and plumbing. The following recommendations conform to section 10.8 in the A-1 192 code covering electrical, plumbing, and heating of recreational vehicles. The solution is approved and recommended by competent health officials. It may be used in a new system a used one that has not been used for a period of time, or one that may have been contaminated.
Before beginning, turn off hot water heater at the breaker; do not turn it on again until the entire recommissioning is complete.
Icemakers should be left running to allow cleaning out of the water feed line; however the first two buckets of ice—the bucket generated during recommissioning and the first bucketful afterward--should be discarded.
[FONT="]1. Prepare a chlorine solution using one gallon of water and 1/4 cup/25 ml Clorox or Purex household bleach (5-7% sodium hypochlorite solution ). . With tank empty, pour chlorine solution into tank. Use one gallon of solution for each 5 gallons of tank capacity . (Or do it a much easier way: Use 1 quart/liter of bleach/50 gal water tank capacity. Put few gallons of water in the tank, then add the bleach.[/FONT]
[FONT="]2. Complete filling of tank with fresh water. Open each faucet and drain cock until air has been released and the entire system is filled. Do not turn off the pump; it must remain on to keep the system pressurized and the solution in the lines [/FONT]
[FONT="]3. Allow to stand for at least three hours, but no longer than 24 hours.[/FONT]
[FONT="]4 Drain through every faucet on the boat. If you haven't done this in a while, it's a good idea to remove any diffusion screens from the faucets, because what's likely to come out will clog them). Fill the tank again with fresh water only, drain again through every faucet on the boat. And yes, it IS necessary to drain through the faucets to flush all the molds etc. out of the plumbing.[/FONT]
[FONT="]5. To remove excess chlorine taste or odor, which might remain, prepare a solution of one quart white vinegar to five gallons water and allow this solution to agitate in tank for several days [/FONT]
[FONT="]6. Drain tank again through every faucet, and flush the lines again by fill the tank 1/4-1/2 full and again flushing with potable water.[/FONT]
[FONT="]People have expressed concern about using this method to recommission aluminum tanks. While bleach (chlorine) IS corrosive, its effects are are cumulative. So the effect of an annual or semi-annual "shock treatment"[FONT="] that [FONT="]only leaves [FONT="]bleach in the [FONT="]sys[FONT="]tem for a few [FONT="]hou[FONT="]rs [/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]is negligible compared to the cumulative effect of holding chlorinated city water in the tank for years....o[FONT="]r [FONT="]worse yet, adding a[FONT="] little bleach to each fill. [/FONT][/FONT][/FONT]Nevertheless, it's a good idea to mix the total amount of bleach in a few gallons of water before putting it into either a stainless or aluminum tank.
[/FONT] [FONT="]An annual or semi-annual recommissioning according to the above directions is all that should be necessary to keep your water tasting and smelling as good as anything that comes out of any faucet on land. If you need to improve on that, install a water filter. Just remember that a filter is not a substitute for cleaning out the system, and that filters require regular inspection and cleaning or replacement.[/FONT]