Fresh Water Tank - Disinfecting

[River Bank]

I drained out all the old fresh water out of my R25.

I now want to refill the tank, but want to ensure that all the "bugs" and "microbes" that might have been living there are "dead" and eventually flushed out.

I went to "West Marine" today and they suggested bleach, but couldn't tell me how much to put in.

Not planning on using this fresh water for cooking, but will use it for washing and cleaning up only.

I need some suggestions.

Bob

 

[RProffer]

You could put a cup of bleach in your tank and fill it, and leave it overnight. You will have to empty and refill the tank at least three or more times to get rid of the bleach taste. The taste won't hurt you. I recommend filling the tank only with the special white RV water hose and using an inline water filter (available at WalMart in the RV section).

 

[Nellie Too]

We have an R-29 and carry 70 gallons of water. When Bob fills the water tank, he puts in about 1/4 cup of bleach. Like you, we use the water for showers, washing dishes, but not for cooking or drinking. Periodically, Bob will fill the tank with water and 2 cups of bleach, let it rock for a day or two, and then flush it twice.

Hope this helps.
Nita and Bob too

 

[knotflying]

A little off topic, but it would be nice if there was a gravity drain to the water tank that allowed you to drain it without having to use the water pump. It would definitely come in handy during those times that you want to winterize and sanitize your tank after storage.

 

[RProffer]

Depending on where you look, the recommended amount of plain bleach to be used to disinfect water for drinking is 1/8 to 1/4 teaspoon per gallon of water. A 1/4 cup per 70 gallon tank is about right to disinfect 70 gallons at the rate of 1/8 tsp in an emergency situation. The bleach is not required if you are getting your water from a reliable source. Do not use scented bleach or bleach with other additives. You should fill your tank with a white RV water hose. A standard garden hose is not safe for drinking water. I also recommend using an inline water filter (available at WalMart in the RV section) to filter out any bad taste. I have had some really horrible tasting water from RV parks and marina's.

Many sites recommend disinfecting your water tank every spring. I have not found that necessary. I recommend disinfecting your tank when it is new, after major work on the water system, or if the water taste or looks strange.

 

[Levitation]

I use bleach in mine also.
After the shock treatment and the rinses I refill with fresh water plus 4 teaspoons of bleach - good to go.

 

[RProffer]

One more thought. If you have city water, then the water is probably already chlorinated. Additional chlorine (bleach) to disinfect the water is not required. I have a well and periodically test the water.

 

[Brian B]

You could put a cup of bleach in your tank and fill it, and leave it overnight. You will have to empty and refill the tank at least three or more times to get rid of the bleach taste. The taste won't hurt you. I recommend filling the tank only with the special white RV water hose and using an inline water filter (available at WalMart in the RV section).

Something I've always wondered about. At my marina the water is traveling through hundreds of feet of black water line before it gets to my slip. Is the use of a white hose for the last 50' really going to make a difference on water quality?? That filter is a good idea. We really only use the water for dishes and showering.
Just curious.

 

[bbrh842]

So that explains my dementia. I drank water out of the hose all the time when I was a kid.

 

[RProffer]

I was distinguishing between a white hose that is made specifically for RV and marine use as opposed to a standard garden hose.

 

[walldog]

You could put a cup of bleach in your tank and fill it, and leave it overnight. You will have to empty and refill the tank at least three or more times to get rid of the bleach taste. The taste won't hurt you. I recommend filling the tank only with the special white RV water hose and using an inline water filter (available at WalMart in the RV section).

Something I've always wondered about. At my marina the water is traveling through hundreds of feet of black water line before it gets to my slip. Is the use of a white hose for the last 50' really going to make a difference on water quality?? That filter is a good idea. We really only use the water for dishes and showering.
Just curious.

Yes, it does make a difference from an ordinary garden hose. The black pipe is approved for potable water, the garden hose is not. Many boaters are using the collapsible hoses from "As advertised on TV". These are not approved for drinking water as per the fine print.

The white RV/Marine hoses are approved for drinking water.

Be careful with filters, some of them strip the chlorine out of the water along with sediment and particles. Your water will not remain bug free if it does not have chlorine in it. We had a whole house filter at our home in Port Isabel. It was too good as it removed the chlorine. After water was not used for a few days and sat in warm pipes, things started to grow in the water. After one summer away from home, we had to do quite a bit of flushing of all our pipes and hot water heaters to remove the odor and I am sure taste (I did not sample it) from the water. We have removed the large filter and have point of use filters for drinking and ice.

 

[Longbranch Louie]

When flushing the tank after the two cup "shock" clorinating, be sure and drain the hot water too. Otherwise your hot water that your wife uses to wash her face will remain strongly bleached.....Im still hearing about that one.

 

[LADYBUG TOO]

I am a retired water systems engineer. I recommend that you be very careful as to the use of household bleach. Some brands contain trace scents that can leave long term tastes in your system. We humans have an incredible sense of taste. Believe me, my water customers taught me that lesson quite well. Some of the phone calls were a bit disturbing! I am not saying that the household bleaches are going to hurt you. The point is that they likely do not have NSF approval stamping for potable water applications. That being said, they are better than nothing. I would recommend that you turn on every outlet on the boat (hot and cold) and pump the tank down, then refill and pump again with just plain tap water. Most state agencies regulating tap water require a chlorine residual of 0.5 mg/l at the most distant end point of the system. Utilities are required to test at specified intervals at sample points in their systems. On our R-29 it took several pump downs to get rid of the non-toxic but foul tasting anti-freeze. It doesn't get that cold here so I sure wanted to get rid of the taste and smell of that stuff.

Pat & Carolyn, Ladybug, Too