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Flushing the Water Tanks

Feb 7, 2011
9
Beneteau 40 Greenport
Hi -

I sail a 2010 Beneteau 40. I was interested in finding a more efficient way than running the taps to flush the water tanks. I bought a pump but cannot seem to snake a hose down far enough when accessing the water tank through the deck fill. Any thoughts on the approach I might take (i.e. using a hose designed for that purpose, or if there is access to the tanks directly) would be appreciated. If this topic has already been discussed, I would appreciate being pointed to the thread.

Best,
Bob
 
Feb 26, 2004
20,886
Catalina 34 224 Maple Bay, BC, Canada
Connect the new pump to the hose that currently connects to the inlet of your fresh water (faucet) pump from the tanks.

Not sure why you'd buy a separate pump to do that, since the one that's there should work just fine.

If you're doing this to clean & recommission your fresh water system, you might be interested in this:

Fresh Water System Recommissioning 101 - Peggie Hall's "Cocktail" http://c34.org/bbs/index.php/topic,5836.0.html
 
Feb 7, 2011
9
Beneteau 40 Greenport
Connect the new pump to the hose that currently connects to the inlet of your fresh water (faucet) pump from the tanks.

Not sure why you'd buy a separate pump to do that, since the one that's there should work just fine.

If you're doing this to clean & recommission your fresh water system, you might be interested in this:

Fresh Water System Recommissioning 101 - Peggie Hall's "Cocktail" http://c34.org/bbs/index.php/topic,5836.0.html
Many thanks for the fast reply and the link to Peggie's "Cocktail".

I am probably over thinking this (or not thinking enough). My freshwater pump works fine, it is just that to flush the tanks takes quiet a bit of time and probably places more wear and tear on the pump than necessary...since I tend to want to flush the tanks after they have been filled with water (about 100 gallon total capacity). Hence the purchase of a water transfer pump that I was thinking to use to siphon the water out of the tank. If I was only putting in 10 gallons or so in each tank and letting the solution slosh around before I drained it, this would not be an issue. However some of the posts that I have read, including Peggie's, say to fill the tank completely (e.g. step 2 from Peggie '2. Complete filling of tank with fresh water. ').

So if I understand your suggestion, it would be to go to my water pump and take the hose connecting to Tank 1, for example, and hook that up to the water transfer pump, and let the water transfer pump do the work. Note that I would only do that after I have flushed the "cocktail" through all of the hoses in the boat (sinks, shower, transom shower).

Thanks,
Bob
 
Jun 18, 2013
39
Beneteau 41.1 Glen Cove, NY
Are you talking about "spring commissioning" i.e. removing the anti-freeze from the tank and lines? Or are you getting stale, foul water from the faucets mid-season? If the former, I usually fill the tank only 1/3 or 1/4 before emptying, maybe twice or thrice, then fill the tank. By the second tankful the water seems perfectly drinkable to me. Bypassing all the faucets with a pump would leave anti-freeze in all those lines, that would still have to come out when you use the freshwater system.
 
Sep 25, 2008
5,541
Alden 50 Sarasota, Florida
If your objective is no disinfect and you are using bleach, the efficacy of disinfection is directly related to residence time. Residence time meaning the duration in which you leave the chlorine solution in the tanks/plumbing. Simply poring it in and running it through results in 'feel good' actions. Leave it in the system overnight before flushing.
 
Feb 7, 2011
9
Beneteau 40 Greenport
Are you talking about "spring commissioning" i.e. removing the anti-freeze from the tank and lines? Or are you getting stale, foul water from the faucets mid-season? If the former, I usually fill the tank only 1/3 or 1/4 before emptying, maybe twice or thrice, then fill the tank. By the second tankful the water seems perfectly drinkable to me. Bypassing all the faucets with a pump would leave anti-freeze in all those lines, that would still have to come out when you use the freshwater system.
Thanks. I am referring to the stale, foul smelling water that I get mid-season. Thanks for the tip on removing anti-freeze from the lines.
 
Feb 7, 2011
9
Beneteau 40 Greenport
If your objective is no disinfect and you are using bleach, the efficacy of disinfection is directly related to residence time. Residence time meaning the duration in which you leave the chlorine solution in the tanks/plumbing. Simply poring it in and running it through results in 'feel good' actions. Leave it in the system overnight before flushing.
Many thanks for the tip.
 
Dec 2, 1997
7,491
- - LIttle Rock
Nowhere is it written that fresh water systems should only be recommissioned in the spring. The instructions: "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. Which can happen if water is allowed to sit in the tanks(s) for an extended period. Put a jug of tap water outside in the summer heat for several weeks and see how good it'll taste. The water supply hose to the dock and your own hose are both sources of contamination if you don't let the water run long enough to flush all that's been sitting in them before filling your tank. You'll know when it has because the water becomes cool...water that's been sitting in hoses will be warm. So if your water supply goes funky, "recommissioning" the system again is the best solution. It's not that hard to do...I always put the bleach solution in last thing before I went to bed...turned on the faucets to drain it when I got up the next morning (brought bottled water to make my morning coffee)...refillled while I was drinking it...by the time I'd finished making and eating breakfast it was done.

Water "treatment" products aren't an alternative to recommissioning. They're for use in boats that take on water from wells and sources other than a municipal water supply.
 
May 7, 2014
135
Beneteau 390 Tiburon
Nowhere is it written that fresh water systems should only be recommissioned in the spring. The instructions: "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. Which can happen if water is allowed to sit in the tanks(s) for an extended period. Put a jug of tap water outside in the summer heat for several weeks and see how good it'll taste. The water supply hose to the dock and your own hose are both sources of contamination if you don't let the water run long enough to flush all that's been sitting in them before filling your tank. You'll know when it has because the water becomes cool...water that's been sitting in hoses will be warm. So if your water supply goes funky, "recommissioning" the system again is the best solution. It's not that hard to do...I always put the bleach solution in last thing before I went to bed...turned on the faucets to drain it when I got up the next morning (brought bottled water to make my morning coffee)...refillled while I was drinking it...by the time I'd finished making and eating breakfast it was done. Water "treatment" products aren't an alternative to recommissioning. They're for use in boats that take on water from wells and sources other than a municipal water supply.
So how much bleach ratio to clean before draining?
 
Dec 2, 1997
7,491
- - LIttle Rock
1 quart bleach / 50 gals water tank capacity. Here are the complete directions (and btw, they are not MY "cocktail"...you'll find the same instructions on just about every RV site on the net. I found 'em in the owners manual for 1985 Sea Ray.

[FONT=&quot]FRESH WATER MAINTENANCE[/FONT]

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.”

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.

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=&quot]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. (Simpler way to calculate: 1 quart bleach/50 gal water tank capacity. [FONT=&quot]Mi[FONT=&quot]x in a bucket or [FONT=&quot]put [/FONT]a [FONT=&quot]few gallo[FONT=&quot]ns of water to the tank before [/FONT][/FONT][/FONT][/FONT]adding straight bleach.)[/FONT]

[FONT=&quot]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=&quot]3. Allow to stand for at least three hours, but no longer than 24 hours.[/FONT]

[FONT=&quot]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. [/FONT]

[FONT=&quot]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 vehicle motion. [/FONT]

[FONT=&quot]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=&quot]People have expressed concern about using this method to recommission aluminum tanks. While bleach (chlorine) IS corrosive, it’s effects are 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. 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=&quot]People have also expressed concern about the potential damage to rubber and neoprene water pump parts. Again—the cumulative effect of carrying chlorinated water is far more damaging over time than the occasional “shock treatment.” 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. [/FONT]

[FONT=&quot]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]


[FONT=&quot]To keep the water system cleaner longer, use your fresh water...keep water flowing through system. The molds, fungi, and bacteria only start to grow in hoses that aren't being used. Before filling the tank each time, always let the dock water run for at least 15 minutes first...the same critters that like the lines on your boat LOVE the dock supply line and your hose that sit in the warm sun, and you certainly don't want to transfer water that's been sitting in the dock supply line to your boat's system. So let the water run long enough to flush out all the water that's been standing in them so that what goes into your boat is coming straight from the water main. [/FONT]

[FONT=&quot]Finally, while the molds, fungi and bacteria in onboard water systems here in the US may not be pleasant, we're dealing only with aesthetics...water purity isn't an issue here--or in most developed nations...the water supply has already been purified (unless you're using well-water). However, when cruising out of the country, it's a good idea to know what you're putting in your tanks...and if you're in any doubt, boil all water that's to be drunk or used to wash dishes, and/or treat each tankful to purify. It's even more important in these areas to let the water run before putting it in the tank, because any harmful bacteria will REALLY proliferate in water hoses left sitting on the dock.[/FONT]