Most Effective Method of Cleanig Water Tanks

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Jun 23, 2005
2
Cal Cal 39 Mackinac Island, MI
What is considered the most effective method of cleaning water tanks. This would include the elimination of any matter in the water tanks, and sterilizing for drinking wayter. Thank you,
 
May 11, 2005
3,431
Seidelman S37 Slidell, La.
Cleaning Tank

I have been looking for the same advice. My water tank is I think fairly clean, but water tastes terrible coming from it. Best sounding advice I have found so far is. Use dish washer soap and some bleach. 1 teaspoon bleach per gallon of capacity. I think I am going to use a little more than that, let it sit for a couple of days. Then flush several times. Will post up how this works when I finish.
 
D

Don't forget the water lines

Rick I

Sometimes it's adviseable to put a stronger bleach mixture in and let it sit in the waterlines for a day or two. If there's an inspection plate on the tank, open it and take a hose down to it and blast away including the top of the tank. Then soak and flush and flush and flush.
 
Dec 2, 1997
9,011
- - LIttle Rock
Follow these directions

Which you could have found by searching the archives for "fresh water"...they're at: http://archive.sailboatowners.com/archive/archiverview.tpl?rid=2005123171411.71&forumabr=aao&fno=2&&model=none&forum=none&andor=wa&keyword=Fresh%20water&pr=p&ssite=HOW&srt=none&start=5&max=100&db=2005&cart=1119627633421464 For some reason, the link isn't posting as it should...you'll have to copy/paste the complete address: archive.sailboatowners.com/archive/archiverview.tpl?rid=2005123171411.71&forumabr=aao&fno=2&&model=none&forum=none&andor=wa&keyword=Fresh%20water&pr=p&ssite=HOW&srt=none&start=5&max=100&db=2005&cart=1119627633421464 I don't know who told you to use dishwasher detergent, but it's a BAD idea. 'cuz it's HIGHLY caustic...if it gets on wet skin, it'll burn you ...so caustic that aluminum cookware should never be washed in a dishwasher...leaving it an aluminum tank for a couple of days will seriously damage the tank. Even if your tank is plastic, leaving it in the system for a couple of days will seriously damage hoses and rubber...mixing it with bleach can produce a lethal gas! Nothing should be left in the tank for longer than a few hours. Recommissioning the system annually according to the directions at the link I provided will leave your water tasting and smelling as good as any that comes out of a faucet on land...and is safe for your fresh water system AND you.
 

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
What the 'pros' are using ....

Expensive; but, DOES the job. It kills virtually ALL species of fungi, bacteria and viruses including those resistant to chlorine. Its a mixture of peracetic acid and hydrogen peroxide - so you need some 'chemistry' background so you dont hurt yourself, etc. http://www.minntech.com/ftg/products/minncare/
 
R

Rich

Hold on to your seat...

Bermuda, because water tanks are one of those issues, like anchors, that generate various responses bordering on religion. So I'm not going to make any bones about it, here are my articles of faith on water tanks: 1. This water isn't for drinking. If you clean the tank immaculately you can try drinking it for a month afterward, but by the end of the season you'll be taking a risk. The populations of little parasites will grow enough to be a problem and the things you'll have to do to keep them down will damage your tank. Keep sealed bottled water on board for drinking and use your tank water for everything else. 2. No bleach. Bleach damages tanks in the long run. Plastic tanks become brittle and pick up a permanent reek of chlorine; metal tanks may be okay, but you have to know a lot about the metal and how it will behave. 3. Inspection ports are a must. If your tank doesn't have them, install some. It's the only way to get at the inside of the tank to scrub slime. If you have plastic tanks remove them from the boat and give them a good scrubbing with a long-handled (new, unused) toilet brush. You can use whatever cleaning stuff you like because your scrubbing and the hose are going to rinse it all out before you put them back. Look at all the connecting hoses and weep; they will probably be disgusting and need to be replaced, or else all this cleaning is for nothing. If you've got big metal tanks you'll have to decide how to go about it, but without an inspection port you'll never find a means short of using a flamethrower to make it clean enough to drink from...
 

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
Disagree ...... this water 'can' be made safe

If you totally shock sanitize (almost sterilize) ALL the system... including the very important tank VENT then place a bacteria blocking 0,2uM hydrophobic membrane filter on the VENT you should have a clean bug free system for quite a long time. The result will be water quality that will remain biologically stable for quite some time. NO vent filter = NO confidence. This is a standard industry practice. If nothing gets IN the tank through the vent those few organisms that arrive with the incomming water will be at and remain at a very low population (titre). Sanitizing the system without also sanitizing the vent (+ adding filtration) .... is simply totally improper, uniformed and quite silly IMHO. Assuming a very low population of incoming organisms when you fill, MOST of the resident mildew, bacteria, etc. spores, etc. WILL enter through the VENT when you draw down the tank. In industry THE MOST important consideration for tank isolation and long term potability is the VENT. I ask you to go carefully look at the present condition of your VENT line .... 99.9999% probability that there is a huge amount of organisms growing there. YES there will sooooooo many that you will actually be able to see the accumulated bacteria and mold/mildew slimes growing there .... then consider that EVERY time you draw down the tank, all these spores are available to continually inocculate the tank. The current 'consumer level' regulations are out of date by about 50 years!!!!! If you dont want to spend the $$ for a proper tank membrane type vent filter .... simply take a BIG wad of absorbant cotton and attach it to the outlet end of the vent, then cover with gauze. Keep it DRY and change yearly - simple and you wont have to clean/sanitize the tank so often. Then you can drink the water with a HIGH degree of confidence.
 
R

Rich

Blinded by science...

Richh, if you're going to make suggestions for using equipment way outside the scope of consumer hardware offered in the boating stores then you might want to include information on how to obtain some of this stuff. And I notice your analysis of filtration doesn't include any information on how to sterilize the equipment at the outset. Autoclaves? Steam treatment? Alcohol bath? We're back to the myth of bleach that we keep arguing about on this topic. Sure, in theory it's possible to sterilize your boat water system to make it possible to safely drink the water but, to anyone who isn't about to dismantle their system every season I suggest you let your bottled water companies worry about the 20-micron filters and you just buy the end product and carry it on board...
 

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
Follow up .... to Rich

The link posted will yield distributors. Sterilization is NOT what a potable water system needs. Shock santization (by whatever means you deem or perceive adequate) will probably reduce the bioburden to to a level that will usually be at a safe limit. A few mircoorganisms wont bother you but a stagnant soup of such in your water system can ... washing dishes, showering, etc. The need for tank visual inspection is important to discover if there are films of bacteria, etc. as a sanitization usually only kills/stuns the upmost layer. CLEANING - to remove the adhered scums of dead cells is probably MORE important than removal/killing of actual organisms - dead cellular debris (metabolites) release that which causes fever, 'trots', etc. There is NO need to sterilize the system, there is NO way you can maintain (or would even want) a sterile system, just a reduction level to 'few' bodies. Its called 'cleanliness'. You'd probably barf If I gave you a glass of water as dirty as most boat water tanks. BTW the federal guidelines are for 1,0uM (absolute) filtration for municipal water sources and from such suppliers as commercial bottled water, beverages, etc. ... to remove/retain those organisms that are resistant to chlorine. I totally agree with carrying on drinking water from a bottle/jug. I use two 5 gallon polycarbonate carbuoys. The important message is to CLEAN the system, then SANITIZE and then protect the bugs from invading down the VENT. If one of those three steps are missing .... you get 'doubtful' water. Your choice. ;-)
 

shorty

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Apr 14, 2005
298
Pearson P34 Mt Desert, ME
Peggy's method

I re-commisioned this spring with Peggy's method (dilute bleach hen vinegar rinse, see her link below) & so far the water is nice & clean.
 
May 11, 2005
3,431
Seidelman S37 Slidell, La.
Just did mine

I just flushed and cleaned mine this week. I used two cups of bleach in a 40 gal. tank. Let it sit overnight. Flushed several times, and it seems to be fine, and tastes just like the tap water I put in it. Has anyone ever heard of adding a little lime juice to each tank? Supposed to help a lot in keeping water tasting fresh and clean.
 
May 11, 2005
3,431
Seidelman S37 Slidell, La.
Question for Rich

If this water is not for drinking, exactly what did the mfgs. install the tank for. And what would you suggest one do for drinking water when out cruising. I do keep ten gallons in plastic jugs for emergency use, but not nearly enough to last for two or three weeks. Just curious
 
R

Rich

The risk is your choice

Easy 'n Shorty, I mentioned below that after you (thoroughly) clean the tank you can probably safely drink the water for a month or so--so it doesn't surprise me that you're feeling like all the water tastes okay at the moment--but you need to be doing this with your eyes open. When you carry sealed, filtered, pasteurized bottles of water on board for drinking, wouldn't you use those first rather than holding onto them for contingencies? The law of averages is with you when you do it that way. Manufacturers provide you with the tanks, but how you use them is up to you. Hikers are told not to drink even crystal-clear-running stream water without filtering it because harmful (as in, makes your gut feel very bad for very many days and can actually kill some people)microorganisms are still there in unknown concentrations. Sealed bottled water is a high-safety form of storage and the wisest choice for drinking water on the boat.
 
Dec 2, 1997
9,011
- - LIttle Rock
Slight flaw in your argument, Rich...

The water in the running stream that hikers should purify hasn't already been purified purified by the municipal water source...the water than goes into most onboard water tanks has. And it's as safe from the tank as it is from the faucet the fill hose was attached to. I know many people (and do it myself) who refill bottled water bottles with water straight from tap. What's the difference between "tap water" that's been been in the tank for a week or two, and tap water that's been sitting in a bottle for just as long as even longer? A bottle that's been opened, exposed to airborne pollutants and any others from handling and maybe even any germs you may be carrying and transfer to it by drinking straight from the bottle...that's safer than water from your tank? Once even a new water bottle has been opened, it's been exposed to any airborne critters that could also pollute your onboard water supply. And if you think you're protecting yourself if you only use your onboard water to wash dishes and bathe, you're overlooking the fact that anything that might harm you if you drink it is also on anything you wash with that water. You wash your hands in it, then pick up a sandwich...you rinse out a mug with it and then fill that mug with bottled water...you might as well just drink it. Water taken on from port in a 3rd world island country is another matter. Now we're talking about the need for water purification, which is a whole different subject. But here in the US, if the water in a tank that's come from a municipal water source tastes ok and smells ok, it's safe to drink. If it doesn't taste/smell ok, it's prob'ly still safe, but it's time to recommission the system to rid of the critters that are non-harmful, but make the water go 'funky.'
 
R

Rich

Slight flaw in YOUR argument, Peggy...

Peggy, if you think that water that's been travelling through municipal water pipes is safer than water that's been purified and bottled in a plant, then, bless you, you don't know enough about what's underground in most cities. My own home town just removed a section of 100-year-old porous clay pipe from our municipal main last year; the water is only pure until it gets to that section, then all bets are off. When chlorinated municipal water is left standing the chlorine eventually evaporates and leaves the water unprotected. Sooner or later this treated water will foul. The water in your boat water tanks is only there a "week or two" if you're using up the water completely in that time before refilling. Otherwise, the organism population in the remaining water gets reduced only by the portion of water removed and proceeds to grow again. The bottled water should be pasteurized (all microorganisms killed by steam-treating the container and boiling the water) and will remain completely unfouled until it is opened. It's almost impossible to control the many factors that introduce impurities into your boat tank water, from the municipal water lines to the hose at the marina to your tanks, pumps, and fittings, so statistically speaking, using bottled water on board for drinking is the safest practice. Do what you like, of course, but do it with your eyes open...
 
Jun 2, 2004
425
- - Sandusky Harbor Marina, Lake Erie
...purified and bottled in a plant...

Whatever they are doing in water bottling plants, tests of bottled water on the retail shelf consistently show levels of bacteria at or above the levels of US municipalities. (Chlorination, and positive pressure keep municipal water good at the tap, despite high levels of leakage measured in most systems.) Unlike milk, bottled water is not distributed refrigerated. Nor is it packaged like Tetra-Pak containers without air. I understand some prefer bottled water, but any safety advantage seems illusory. Keeping the water moving in your unboard system is key to keeping it good. Not using it for drinks, coffee, or cleaning is a good way to ensure it stagnates. David Lady Lillie
 
A

a poor old sailor

Slight flaw in immune systems

Ya know, if you wanna make a case for water that tastes good then please go to EXTREMES. But being so afraid of getting 'ill' from tanked water is ridiculous. As long as your tank is reasonably clean (see Peggy's method) and your source water is reasonably clean water (no giardia, cholera, hepatitis, etc...), you should have no problem with drinking water from your tank. If you do get sick from it, you oughta have your doctor check out your immune system. Or maybe your immune system is so freaking weak already because you sterilize everything you touch that your body has no idea how to deal with any introduced 'bug'.
 
Feb 26, 2004
23,320
Catalina 34 224 Maple Bay, BC, Canada
Major flaw in lots of things, but

why beat this to death? If you want to drink out of your water tanks, clean them up. if you don't, bring bottled water or buy Coke fr'crissakes. Geez, why argue? Your boat,your choice. Stu PS We use our tanks for showering and washing. We have a few 2 gallon jugs for drinking and cooking that we fill up with tap water. We don't do Perrier or Evian, and prefer rum with your choice of assorted beverages, plus beer. Longest stay away from a dock was 8 days and we survived. We have about 80 gallons in the boat's water tanks.
 
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