Cleaning large built in water tanks


Aspiring Anarchist
Santa Cruz
unscented household bleach: 1 part per 1000. Add a carbon filter to remove any residual taste

Brush your teeth! More seriously the municipal system didn't have enough residual chlorine where you filled it.
This worked for us 30 years ago. We always had the best water compared to other boats, and all we did was put a small amount of bleach in every time we filled the tank. If I remember, the strength of bleach varies a bit around the world. I think I had to adjust the dose to compensate.

When we got water in the marquesas, we also refilled a 5 gallon jerry can we kept in the cockpit. Didn't put any bleach in the jerry can it. It turned green after a few days. The water in the main tank was fine. I think the water in the marquesas is not treated in any way. It is just stream water from up in the hills above all the permanent residences.


Aspiring Anarchist
Santa Cruz
In the UK, unlike the USA, the 'bleach' available retail can have other ingredients that you don't want in your potable water. The cleaning fluids which brewers use to sterilise their equipment offer an effective and cheap alternative to the stuff sold in chandleries/camping stores.
You have to be careful in the US also. Some "bleach" products have other crap in them besides sodium hypochlorite solution. Reading the label carefully can help you figure out which one you want.


Westbrook CT
I was curious about ChatGPT and wanted to see what it would tell us to do:

The best way to clean a water tank in a boat will depend on the materials the tank is made of and the level of buildup or contamination present. However, here are a few general tips:
  1. Empty the tank and rinse it out with fresh water to remove any loose debris.
  2. Mix a cleaning solution of water and a mild detergent or bleach. Use a non-toxic, biodegradable cleaner if the tank will be used for drinking water.
  3. Scrub the inside of the tank with a brush or a cloth, paying special attention to areas with buildup or stains.
  4. Rinse the tank thoroughly with fresh water to remove all traces of the cleaning solution.
  5. Sanitize the tank with a solution of water and chlorine bleach, or with a commercial sanitizing solution.
  6. Leave the sanitizing solution in the tank for at least 30 minutes before rinsing it out again with fresh water.
  7. Leave the tank open and allow it to dry completely before using it again.
It is also recommended to get professional help if the tank is not easily accessible, or if you suspect any contamination or buildup that might need heavy cleaning.

Kinda scary...

I also asked it how to answer if my wife asked me if she looked fat. That was classic.


Super Anarchist
internet atm
I also asked it how to answer if my wife asked me if she looked fat. That was classic.
there is a correct answer to that one
i found it quite by accident
the correct answer to the question
" do these jeans make my ass look fat ? "
" nope ... all the cream buns and doughnuts you ate made your ass look fat .. the jeans are fine "

proof that this is indeed the definitive correct answer is .. i have never been asked again .. so obviously it is the correct one