Bleach and water tanks

[Art]

Originally Posted by AusCan

Dave,
Why do you see a problem with the chlorine level decreasing? The chlorine has already done its job and killed any bacteria in the tank. It's not like a swimming pool where contaminants are added constantly, and free chlorine is required all the time.
No need to add more chlorine to your drinking water unless you add more bacteria.

IMO... It is good to add a touch of chlorine [bleach in a bottle] in every second to third tank fill up for preventative maintenance against bacteria and other items. Depending on whether or not tank water is used for drinking would weigh heavily on how much and how often chlorine is added.

[psneeld]

rather than random clorine adding, testing seem in order to make sure if you are getting treated municipal water, it remains slightly clorinated.

my friend who is a municipal water engineer uses a simple pool clorine test kit.

ANY trace of chlorine is OK in his book, anything more really isnt necessary or desired, especially for those of us who drink from our tanks.

[OldDan1943]

When one is going to be gone all winter, there is something called "red pop" used to decommission you FW system for an extended period of time. I have never used it. One advantage to "red pop" is you know when you have flushed the tank and water lines enough, color gone.
Some folks with aluminum FW tanks use a non-chlorine bleach. You can buy this peroxide based non-bleach at Publix, in a jug. I may start using that to lengthen the life of the water tank for the next owner.
Remember to flush out your water hose from the dock too.
I drink, shower, wash clothes and dishes, use it in 'throne.' with the water in the FW tank. My main filter is on the dock and I have a filter under the sink in the galley. I guess it is recommended to use a charcoal based filter there. I do not have a strainer to the inlet for the FW pump.

[dhays]

Originally Posted by AusCan

Dave,
Why do you see a problem with the chlorine level decreasing? The chlorine has already done its job and killed any bacteria in the tank. It's not like a swimming pool where contaminants are added constantly, and free chlorine is required all the time.
No need to add more chlorine to your drinking water unless you add more bacteria.

Not a problem per se, but keep in mind that chlorine disinfects, it does not sterilize. The difference is that disinfection doesn’t really kill off all the bacteria nor take out all the spores. A small residual chlorine amount takes care of them. Since your tank also has a vent, that is a route for contamination. That is why public water systems aim for .2-.5 ppm of free chlorine at the tap. The water is disinfected at the plant, but needs to stay that way until delivered to the customer.

Most recommendations for private systems with stored water are for free chlorine of about 1 ppm.

[dhays]

Originally Posted by psneeld

rather than random clorine adding, testing seem in order to make sure if you are getting treated municipal water, it remains slightly clorinated.

my friend who is a municipal water engineer uses a simple pool clorine test kit.

ANY trace of chlorine is OK in his book, anything more really isnt necessary or desired, especially for those of us who drink from our tanks.

I think this is a good idea and I would agree that if a pool kit can detect it, it is probably adequate.

[sunchaser]

So, all this detail aside, any first hand knowledge on bad Municipal dock water? Mexico - I could fill a page or two of Montezuma's revenge tales.

[Roger Long]

Are there any special issues with fiberglass water tanks? We're also bottled water users and getting tired of dealing with all the plastic jugs. My concern is not critters but chemicals that might be leaching out of the 1975 vintage fiberglass. Our tank is built in to the keel so made of the same stuff as the hull and not a free standing tank.

I think a good filter plumbed in under the galley sink should let us break the bottle habit but would like some encouragement.

[OldDan1943]

Originally Posted by Roger Long

Are there any special issues with fiberglass water tanks? We're also bottled water users and getting tired of dealing with all the plastic jugs. My concern is not critters but chemicals that might be leaching out of the 1975 vintage fiberglass. Our tank is built in to the keel so made of the same stuff as the hull and not a free standing tank.

I think a good filter plumbed in under the galley sink should let us break the bottle habit but would like some encouragement.

Have you considered replacing the water tank with either aluminum or stainless or plastic?

[psneeld]

fiberglass with gel coat interior more than 10 years old is probably as inert as anything else on the planet.I would prefer a gel surface for cleaning, but plain polyester is probably fine.

I would consider changing to plastic or aluminum as downgrading.

I would still send it through a 2 or 3 stage filtration to drink, but for wverything ekse...no big deal.

[dhays]

Originally Posted by Roger Long

Are there any special issues with fiberglass water tanks? We're also bottled water users and getting tired of dealing with all the plastic jugs. My concern is not critters but chemicals that might be leaching out of the 1975 vintage fiberglass. Our tank is built in to the keel so made of the same stuff as the hull and not a free standing tank.

I think a good filter plumbed in under the galley sink should let us break the bottle habit but would like some encouragement.

I don't know, but I really doubt that you would face any harmful level of chemicals off that old fiberglass tank. I wouldn't hesitate to drink the water from your tanks.

[Larry M]

Originally Posted by OldDan1943

Have you considered replacing the water tank with either aluminum or stainless or plastic?

Why? We have two, ~150 gallon fiberglass tanks on our Krogen and the water is totaly tasteless. We’ve never added chlorine. Maybe once a year I take a hose with a spray nozzle and clean the insides just for pierce of mind but that’s it. A lot of our water system to the taps is copper so I don’t know if that helps?

Many major and recognized boat builders have used fiberglass tanks with no reported health issues for years.

[Giggitoni]

The above, with a few exceptions, ignore the water tank material. We have aluminum FW tanks. I collected a sample from our FW tanks and submitted it, under chain of custody, to a certified laboratory. We had the laboratory analyze for the presence or absence of metals as well as standard drinking water parameters. Aluminum came back above National Drinking Water Standards. As a result, we don’t drink water from our FW tanks.

Collecting and submitting a water sample to a laboratory is cheap! Test for “drinking water quality” and add metals to the analysis. Then make a decision whether to use it for drinking. My two cents.