Originally Posted by chouliha
Time to shock your tanks with bleach. Use the search engine
to look up peggie hall. We have used her advice for decades on keeping our tanks clean. We do a shock treatment about once a year or when we can get good potable water and in a marina.
He doesn't have to search for me... Here are the directions (which are also included in both my books):
FRESH WATER MAINTENANCE
(excerpt from "The NEW Get Rid of Boat Odors
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. There are all kinds of products sold that claim to keep onboard water fresh, but 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 and all bleach solution has been flushed out of it. 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…bleach does absolutely nothing to improve the flavor of good Scotch!
1. Prepare a chlorine solution using one gallon of water and 1/4 cup (2 oz) Clorox or Purex household bleach (5% sodium Hypochlorite solution ). With tank empty, pour chlorine solution into tank. Use one gallon of solution for each 5 gallons of tank capacity. (Those are the “official” directions. They work
out to 1 quart or litre of bleach/50 gallons of water tank capacity , which is MUCH easier to calculate!)
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.
3. Allow to stand for at least
three hours, but no longer than
4. Drain through every faucet on the boat
(and 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.
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 by vessel motion.
6. Drain tank again through every faucet, and flush the lines again by filing the tank 1/4-1/2 full and again flushing
with potable water.
People have expressed concern about using this method to recommission steel
tanks. While bleach (chlorine) IS corrosive, its effects are cumulative. So the effect of an annual or semi-annual "shock treatment" is negligible compared to the cumulative effect of holding chlorinated city water in the tank for years. And it’s that cumulative effect that makes it a VERY bad idea to add a little bleach to each fill. Not only does it damage the system, but unless you add enough to make your water taste and smell like a laundry
, it’s not enough to do any good. Even if it were, any “purifying” properties in chlorine evaporate within 24 hours, leaving behind only the corrosive properties. Nevertheless, it's a good idea to mix the total amount of bleach needed for recommissioning in a few gallons of water before putting it into an empty stainless or aluminum tank.
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.
--© 2019 by Peggie Hall