Adding Bleach to Water Tanks

HopCar:
That did not take long. The "Puriclean" product you mentioned has an active ingredient of sodium DiChloride the solid form of chlorine like used in swimming pools. It is National Safety Foundation approved for use in water systems. So both clorox and puriclean both use chlorine as the disinfecting agent. The puriclean product appears to do the shock type treatment requiring the rinse and flush. I do not think it maintains a residual.

"No, what was stated was 50 parts of chlorine to one million parts of water. Not 50 parts of Clorox."
That's what I figured but I couldn't get my head around the math last night!


The same folks who make Puriclean also make tablets to add to water tanks if your not sure of the water purity. They are called Aqua Clean Tabs.
They don't make the water any safer than household bleach but they claim it's safe for aluminum tanks and figuring the dosage is easier. The cost is more than bleach but the tablets are easier to store.

http://www.cleantabs.co.uk/aquacleantabs.htm
Treating Stored Water


Aqua Clean Tabs and Aqua Mega Tabs are specifically formulated for maximum microbiological control in stored water, and will keep the water fresh. The water tank and system or container and filling hose should be periodically cleaned and purified with Puriclean

• Aqua Clean Tabs: 1 tablet purifies 25 lts (5 gals) water
• Aqua Mega Tabs: 1 tablet purifies 225 lts (50 gals) water

I can see where they (Puriclean) tablets would make things easier, greater shelf life and certainly the dosage math. I do the math all the time and it does not get any easier. Usually have to figure the diameter of a new municipal line x distance installed and eventually get to the volume then the 50ppm dosage, etc...I have memorized the .785 x diameter squared x 7.5 equation. The new thing now is that you have to Un-Chlorinate prior to flushing into a waterway, the trick there is to pass it through a sock filled with Vitamin C tablets. Asorbic acid immediately removes the Chlorine.

Here is something I learned about boat water. Seagull filters they remove microbes and Chlorine. So with one of these filters at the galley sink I can give my whole system a heavy shot of chlorine when needed and still have potable water. It may be necessary to wait awhile to take a shower. Using this method I rarely have to do a major shock treatment. I developed this method because the water sources where I cruise are not always reliable. So if I have to take on questionable water the chlorine goes in with it and the filter sees to our potable water.

Boy - This is interesting, informational boat-water stuff. Thanks!

I simply add about 1/2 cup Clorox to each tank every third to fourth tank refill. Total gallons is 77 - in two tanks. I figure after three refills the amount of previous Clorox residual is minimal. I also keep close olfactory review of Clorox odor out of tap. If it becomes too pronounced then I simply let the refills amount to 5 or 6 between adding any more Clorox.

Also, we bring drinking/cooking water and other refreshments aboard for our jaunts. We never drink out of or cook in boat's freshwater. We do wash/rinse dishes in it. I use it to rinse after brushing teeth... gives me another way to keep tabs on boat's water. It always looks crystal clear in a glass.

I think I did the math correctly, but with 7% bleach solution out of the bottle, about 10 oz will treat 200 gals up to 2PPM.

Tom

At 2ppm it takes roughly 28 gallons of clorox to treat 1,000,000 gallons of water. 200 gallons of water is .0002 million. .0002 x 28 = .0056 gallons. There are 128 oz. per gallon so it is less than one oz of clorox to treat 200 gallons.

tank water

I never drink the tank water. My daughter got real sick one time, some sort of bacteria.

I use a Seagull filter. You can put dirty water from a puddle thru this filter and still drink it. It's a little pricey, about $400. The filters last 2 seasons and cost $60. You can't put the pink stuff thru it, you have to remove it when you winterize.

I just read up on the Seagull filter system is does look impressive in filtration capabilities. It lists the really large bacteria and pathogens such as Giardia and Cryptospordia as being effectively removed. Personally, I would rather kill the little fellows rather than catch them. Most water born viruses and most of the other bacteria found in water are smaller than the .4 micron that filter system is capable of catching. What is somewhat interesting in the filtration processes for water is that particles and pathogens have a tendency to gather together based upon there positive/negative charges which helps to make the filtration more effective. Most water plants that I have been associated with will often add an ionic polymer that assists in the process this floculation process creates the binding of those bacteria and particles prior to filtration = larger particles more effective with whatever type filter is being used. Temperature and Ph also effect the entire process. The plants still use a process of either ultraviolet light and/or chlorination to actually kill the pathogens sometimes both are used in the total process. It is desired to maintain a chlorine residual to treat anything that may occur in the distribution side of the the system. Bacteria and viruses often are in a size range of 0.01- 1.0 micron. So yes, the Seagull filter will remove most by not all. A combination of filtration and chlorination has been and will probably always be the standard in the water industry.

gar said:

Hello all, I have been told to add a small amount of bleach when filling the water tanks to help keep the bugs at bay. Anyone know the right amount per gallon which is safe. We don't drink our tank water, but want to keep it at a safe level just in case someone does. Thanks Gary

Click to expand...

There is a much better and safer way to preserve the freshness of water than with household chlorine which affects smell and taste of water, and is short lives as it evaporates. The other way is to use, already mentioned in this thread, stabilized chlorine aka chlorine dioxide. It is safe for drinking and for any and all installations. Small amount keeps the water fresh and potable for up to 5 years. I never had any problem with my fresh water and water tank since I disinfected the tank and started using PUROGENE just after we've got our boat four years ago.

I just add more water to the tank with a prescribed amount of PUROGEN as needed ... no slime, no aftertaste, just fresh water and clean tank at all times. Chlorine dioxide is used for decades by food industry, air lines, cruise lines, etc. It is sold under a few different brands by various outlets.

I prefer the liquid (PUROGENE) over the tablets (AQUA CLEAN) as it gives me a way to mix and add any amount of water to the tank.

PUROGENE
https://readymaderesources.com/product/water-purification-32oz-purogene-free-shipping/

AQUA CLEAN TABLETS
http://www.hopkins-carter.com/aqcltamflpso.html

Hope this helps ...

Chlorine Dioxide aka Purogene is indeed effective in killing the bugs. Different chemical make-up than Sodium Hypochloride but basically provides the same disinfection results. The use of Clorox is simply more readily available and probably is already on board.
I have one problem that I have yet to get my head around though on many of the advertising promotions and in most of our discussions about water. That is at what point in the water cycle do we determine the use of "Fresh" when referring to water. I generally accept that to mean non-salt water but its use today and in ads seems to me to be used like its newer and therefore better. It is actually the same water that has been on this planet for millions of years. I don't think we have made any new water nor have we lost much over those millions of years maybe a few gallons lost on space flights but that is about it.

I the days of service, 4 oz bleach to 100 gals of water was the norm. 2-10 ppm Chlorine.

Indeed, bleach is readily available and effective when water is treated often. Long term storage is where it falls short ... like when a boat is on the hard or in storage for extended length of time, especially during warm season.

ulysses said:

That is at what point in the water cycle do we determine the use of "Fresh" when referring to water. I generally accept that to mean non-salt water but its use today and in ads seems to me to be used like its newer and therefore better.

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Fresh water term often means non-salty, especially around boats. In context of this discussion fresh means not stale, not spoiled, and/or palatable and fit for drinking ... but I think you knew it already ...

I installed new tanks in my boat in the 90's and a guess is 94-95. I washed the tanks the best I could, rinsed them many times then put them in place. Stainless and food grade. I have never used bleach in my water system but I do have four filters. One before the tanks, one before the pump, one after the pump and one more under the galley sink with it's own faucet. I have a niece who only drinks bottled water. She was aboard one day and I did a blind test with her bottled water and my boat water. She could not tell the difference. We drink our water, I lived aboard 20 years and always will.

Filtering is the way I went. Chlorine isn't good for the body. Studies done with people who drink water purified by the iodine tablets, like peace corps workers in Africa, showed a remarkable lack of cancer in their lives. Something to think about.

Capthead: Excellent point, on the cancer causing but not necessarily as it pertains to boat tanks other than those left full for very long periods of time. Going a little deeper into the chlorine/water disinfection than should be necessary but... As chlorine attacks the pathogens in water chemical changes take place. The by products of that reaction are grouped into two groups Trihalomethanes and Haloacetic acids, both have been shown to cause cancer. They are usually found at the end of municipal water lines and locations where water has been disinfected and left to sit. Flushing removes them. If you live on the end of a cul-de-sac you should see your water department flush at least annually to clear those out of the system. On a boat I would recommend flushing your tanks at least twice a year if you disinfect with any type of disinfectant. The EPD started requiring testing for those by products about six years ago.
I spend a few months a year in Nicaragua building new water wells and distribution systems in remote villages and have found it surprising how many people in this world do not have access to anything close to clean drinking water. 3 out of 4 newborns die from water born diseases in that area the first year of life. Those that survive develop some immunity to the bacteria but are still exposed to all the other toxins, viruses, nitrites, etc..
Since I am living and working in the villages before the systems are completed I usually carry my own supply of water and a prescription of Cipro.

ulysses, you have an interesting life. I remember back in my college days taking geology and we had a petroleum geologist who taught most classes. He said, oil is always a good field to be in but in your lifetime ground water will become most important and good clean drinking water.

That was 1966. Here in Orange County, CA they are putting clean sanitation water in the ground and a mile away pumping fresh drinking water for the cities. My brother works for a company the monitors the ground level so they don't pump more or take more and keep the ground level. This is by their satellites that can see 1mm of movement.

There are filters that will remove chlorine and even putting a glass of water in the sun for about an hour will remove it.

So they have a mile of filtration? Your geology prof. was right especially where you live. I know the drought has many concerned and water has always been a critical issue out there. I just hope that we have not waited to late to realize its importance.

That program is a decade old or so and some cities refuse to use that water. My slip neighbor retired from the City of Orange as dept head for the water dept. He refused it for Orange but he's been retired about five or six years now so who knows. He also wouldn't fluoride the water.

LA's water comes from way north and the Colorado River mostly. OC has to use other means. This drought has been bad on the entire state but we are finally seeing rain.

It was a god send for me replacing my deck, though.

Drink a few glass of a good red wine 1st, that should get rid of anything that's buggy, and if still bothers you try again, keep applying the wine until it doesn't matter anymore.

I'll drink to that!!

That may work, but I prefer freezing the water in small cylinders with a hole through the center then then pouring Makers Mark on top for disinfection then drink.

I found Scotch is an excellent disinfectant and blends real well with filtered water.

Tank you Ulysses... Great explanations.

A very interesting read regarding water: Cadillac Desert: The American West and Its Disappearing Water, Revised Edition: Marc Reisner: 9780140178241: Amazon.com: Books

I don't recall the copyright date, and it's been a while since I read it. Even though the material may be dated, it's a fascinating read, particularly if you happen to reside in one of the areas covered by the book. For those in SoCal, as I recall, the book's author's premise is that human life at the western edge of the Mojave Desert is simply not viable in the long term, due to water (or lack of it) issues. As desalination and waste water reclamation are moving to the forefront these days, caused in part to the recent drought in SoCal, that premise seems to be right on the mark.

I realize this posting somewhat drifts from the original question regarding adding bleach to water tanks aboard recreational vessels. I apologize for the thread creep. As a boat owner, I am concerned with perhaps not the carcinogens present in boat water tanks, but certainly the potential for equally-threatening infectious "bugs" (viral and/or bacterial) that lurk down there in the dark. There are seemingly as many "fixes" as there are "fixers" willing to share on this forum (and others). This isn't all bad, but sorting through them is a bit of a challenge.

For what it's worth, my "fix" has been replacement of an aluminum water tank with one made from 316L stainless, and annual shock treatment of the tankage and water system with bleach, per Peggy Hall's recommendations. So far, so good. Knock on wood, of which I have more than enough, thank you.

Regards,

Pete