cleaning out freshwater system

[Woodsong]

So our old boat that is new to us has some added tankage for freshwater. *It looks like we hold about 300 gallons, +/-. *Tanks are about half full and water has been sitting in them for who knows how long since we don't winterize down here. *What's the best way to (quickly) clean out the lines and "sanitize" everything? *Put a little bit of bleach in the tanks with existing water and flush it all out and then refill with new water? *How much bleach? *Actually, bleach is probably a very bad idea as I am pretty sure the bleach will react with the plastic lines/fittings/etc. and degrade the plastic. So, what to do? * *I didn't have to ponder this with my newer boats but I still like this old boat better!

 

[Steve]

Peggie Hall specializes in that sort of thing along with holding tank problems, this address is for her recommended treatment,
Good luck,
Steve*

http://www.guildmark.com/crumpet/Water%20Tank%20Shock%20Treatment.doc

 

[AllanY]

Woodsong

The Australian water guide lines for potable water say 35 mm chlorine per 1000 litres of water
just leave in the tank overnight then all the bugs will be dead
I would then pump out the tanks then refill

Pool chlorine is fine.

Allan

 

[RT Firefly]

Hiya,
** Iwould think 35ml (instead of 35mm) would be the correct measure but even that amount seems low, to me, *for 1000l...

 

[Keith]

I shock with 1 gallon of* bleach per 100 gallons of water. Add the bleach, then fill the tank completely. Run it through all the cold water faucets (I don't like it to mix in the hot water heater because it takes forever to flush out). Remove the screens from all the faucets so they won't trap the crud that comes out. I let that sit from 4-12 hours. I have large FW tanks, so I pump those out with a 110V puppy pump, then fill with fresh water and flush the lines out. Repeat that once and you're good. Oh yea, don't forget your fill hose if you're hooked to shore water. When I'm flushing the lines with the chlorine solution, I hook up my shore water hose to an outlet and fill it with the bleach water too.

Bleach won't react with most plastics and only slightly with SS, but not enough at this strength and time to do any harm.

 

[HeadMistress]

Steve wrote:

Peggie Hall specializes in that sort of thing along with holding tank problems, this address is for her recommended treatment,
Good luck,
Steve*

http://www.guildmark.com/crumpet/Water%20Tank%20Shock%20Treatment.doc

Please kill that bookmark and disregard it.* I have NEVER recommended using anywhere NEAR 8 oz of bleach/10 gallons of water!

I have no idea who uploaded quite a bit of material from a chapter in my book along with their own idea of how much bleach to use.** The correct ratio is about 2 oz bleach-5 gal water, which works out to about 1 quart (liter)-25 gallons of water.

*

 

[skipperdude]

I work in Food Service.*
*
50 parts per million kills everything.

Federal and state guidelines.

SD

 

[Woodsong]

what's the translation of 50 parts per million in ounces per gallon? *

 

[RickB]

Woodsong wrote:

what's the translation of 50 parts per million in ounces per gallon? *

About 3 drops**

*


-- Edited by RickB on Friday 6th of August 2010 10:43:26 PM

 

[sunchaser]

On a Searay I had at Lake Powell, the hot water heater was the stinky item, so I did insure*the water heater indeed got sanitized. Many rubber products do not like high dosages of bleach, so flush ASAP after a shock. For general maintenance purposes, I use 1 tsp per 20 gallons. Many bleaches are watered down going into the bottle, so look for a*range of *5-7% hypochlorite.

 

[Steve]

Peggie and others, sorry that link turned out to be bogus!
I've tried to delete the link but the editing period seems to be over.
Please disregard,
Steve W.

-- Edited by Steve on Saturday 7th of August 2010 09:07:35 AM

 

[Keith]

There's a big difference between using bleach to sanitize water for drinking and sterilizing / shocking the system. The lower concentrations listed below are for how to treat your drinking water. The higher ones are for shocking and cleaning the system, and that final mix is not to be consumed!

 

[HeadMistress]

sunchaser wrote:

On a Searay I had at Lake Powell, the hot water heater was the stinky item, so I did insure*the water heater indeed got sanitized. Many rubber products do not like high dosages of bleach, so flush ASAP after a shock. For general maintenance purposes, I use 1 tsp per 20 gallons. Many bleaches are watered down going into the bottle, so look for a*range of *5-7% hypochlorite.

When it's only the HOT water that smells like rotten eggs--cold is fine--that's a sure sign that the anode in the water heater has failed...and no amount of "sanitizing" will fix that, only a new anode (or water heater).* Cheaper water heaters don't have replaceable anodes...the inner tank is anodized aluminum...when the anodizing wears off, the only cure is a new water heater. However, your SeaRay had a Raritan water heater...one of the higher end brands that have glass lined tanks and removeable anodes, just as household water heaters do.* Replacing the anode is an inexpensive and easy job.

Vic Willman at Raritan sent me the following several years ago...it explains more about the funtion of anodes than you prob'ly want to know:

Anodes are included in the water heater of glass-lined steel tanks to protect the inside of the tank against corrosion from acids in the water, stray electrical currents, etc. Glass lined tanks, when the water heater is being built, are heated up red hot. Then glass powder is sprayed inside the tank and it adheres upon contact. However, it doesn't cover every single crack and crevice inside the tank - it should, but in actual practice, it doesn't. The purpose of the anode is to protect those spots inside the tank that have not been glass-covered from rusting away prematurely. The anode is eaten away, rather than the tank being eaten away. Kind of a backup to the glass lining. The anode is a magnesium rod, about 3/4" in diameter that is attached to the inside of the hot water "out" nipple, via a plastic coupling. It is electrically isolated from the fittings and from the tank. It extends all the way across the inside of the tank, stopping just short of the other side. There is an iron rod in the center of the magnesium that supports it, the iron being stronger than the magnesium. As the magnesium is eaten away and the iron rod exposed, there's a chemical reaction between the water, the iron and the magnesium that causes the "rotten egg" smell. Replacing the anode and flushing out the tank will usually make the foul smell go away.
The same thing is done in electric water heaters used for residential application, but the anode extends down into the tank from the top. The actual tank in residential applications usually develops a leak well before the anode is eaten away, requiring replacement. You'll note that it's not unusual for a glass lined water heater on a boat to last 25+ years - try and find a household water heater that'll last even half that long.


Btw...not a problem, Steve...it's gone from the site.* I've been forced to accept these things occasionally as just one of the hazards of posting on the 'net...you're gonna get misquoted.


-- Edited by HeadMistress on Saturday 7th of August 2010 03:00:10 PM

 

[sunchaser]

Peggy _ I'm sure you are correct on the anode needing replacement from time to time, but in the hot environs of Lake Powell even with a good anode the rotten egg smell occurred over a winter in a drained tank that was backfilled with RV antifreeze. This happened on two different and new (0-3 years old) Searays. Shocking with bleach in the spring and fall and flushing cured the problem.

 

[Keith]

Speaking of water heater anodes, mine needs replacing about every three years. It's time now. Here's the last one I pulled after 3 years.

 

[Woodsong]

Well, it seems I need to do more than just add some bleach to the lines! lol!!!
We spent the weekend on the boat for the first time Had a few little things pop up but the most interesting was with the water tanks and the water lines!

I have decided i am going to either replumb the boat or at least replace most all of the line fittings. Previous owner just used metal screw down clamps for his fittings. I have had 2 instances of the fittings coming loose out of the blue which is irritating.

As well, I think I learned that I need to clean out the tank vent line! I went to fill the tanks up today as they were only about 1/8 full. Old metal tank has been replaced with 2 large poly tanks under the aft bed and the tanks are connected together. So my son tells me after a few minutes that the tanks are full as water is coming out of the fill pipe. "No way," I say to myself. So down to check the tanks and to my surprise i see the aft bed raised up off the bed frame!! EEKK!!
I soon discovered the tanks were NOT venting at all and the water was wanting to displace the air and wow- never new a poly tank could expand like that!!
Doesn't seem any damage was done but this week I will have to pull the vent line and the fitting @ the hull and clear it all out.

 

[FF]

and wow- never new a poly tank could expand like that!!

Remember that if you upgrade from iron to polly fuel tanks.

The difference is the polly fuel tanks STAY expanded after filling , so they are not strapped down hard till after their expansion.