How to stop your water tasting like crap

Ever wondered what potential harm lurks in your water tank – and how to fix it? Here’s how to stop your water tasting like crap

Remote outback Central Australia in summer is one of the last places on earth you would want to discover your water supply tastes like crap. I’ve been there, and I’m lucky taste was the only issue. Water tanks can play host to all manner of disease-causing agents and running out of good water out there can be deadly.

With the benefit of hindsight, let’s rewind the story and establish a good potable water regime starting with choosing the right tank, preparing and filling it, treating water, and finally, preparing the tank and your RV for an extended lay-off period.

Blue poly water tank in steel shroud


Types of RV water tanks

There are myriad different water tank set-ups for every RV application. RV water tanks are commonly made from polyethylene (PE) in varying degrees of hardness, polyvinyl chloride (PVC) which can be hard or soft (in the case of a flexible bladder), aluminium and stainless steel. Weight and storage location are often the biggest determinant of the tank material chosen. There are specific standards you should look for when setting up a new potable water system in your RV.

Drinking water

For drinking water, look for a tank that complies with Australian/New Zealand Standard AS/NZS 4020:2018 Testing of products for use in contact with drinking water. Drinking water tanks are often (but not always) blue in colour. Drinking water should be kept in a separate tank, filled from a trusted source and delivered through a separate pump and filter to minimise chances of cross-contamination.

Crap water, filling a trailer with hose 

General potable water

For domestic supply (kitchen tap, shower, etc.), Australian Standard AS2070:1999 Plastics materials for food contact use (commonly referred to as ‘food grade’) is okay, but if you can go for AS/NZS 4020:2018 that’s even better as you’re likely to ingest this water in some form. Treat general potable water in the same manner as drinking water.


Crap water, Safetank

Tip: A space-saving innovation from Safetank allows you to keep general potable water and greywater in one aluminium outer tank using a double internal bladder system.

Don’t forget everything else…

The tank is only one part of the overall potable water system in an RV. It is important to remember that every pipe, hose, fitting, pump and filter that comes into contact with water has an influence on the quality and taste, so use drinking water safe equipment wherever possible.


Preparing your new tank

While it might be considered a fresh start, a new tank will invariably contain residue and swarf from the manufacturing process and must be thoroughly prepared before first use. This was my first downfall as the bladder we used was not flushed properly before filling and heading into the red centre.

To prepare a new tank, you can use oxidising tablets or liquid, which are very safe and effective and leave minimal residue. The bicarb and vinegar or bleach flush methods that I detailed in my previous guide have been used since Adam was a pup. Make sure whichever method you choose is safe for the tank as per the manufacturer’s recommendations and ensure the solution completely dissolves, as powders can block small lines and fittings.

Open every tap in the RV until water flows, hold water in the system for as long as recommended, then flush through several times and your new tank is ready to use.

crap water, different hose types 

Filling your tank

It’s important that your filling equipment is suitable for contact with drinking water. This was my second downfall as a regular garden hose was used. The result was that world-leading Melbourne quality tap water tasted strongly of plastic. You live and learn! Always:

  1. Start with a trusted water source.
  2. Use drinking water safe filling equipment.
  3. When in use, full is best as it stops water sloshing around and limits growth of nasties.
    Follow your manufacturer’s recommendations for getting the most water into the tank (i.e. fill from the bottom, fill on an angle).

Rvd042 Ed Guide Water Tank Hygiene 4b1 600px Chemical Tablets Cropped

Keeping drinking water safe

If you’re planning to be away for a while and refill on your trip, your water tank may host nasties from the visible such as larvae, algae and mould, to the largely invisible such as heavy metals, bacteria, viruses and protozoans. Lack of a bad taste is no guarantee the water won’t make you sick. Always:


  1. Use a trusted water source or pre-treat the water.
  2. Treat the water in the tank periodically as instructed on the pack.
  3. Ensure all tank breathers are adequately guarded from insect intrusion.
  4. Don’t be tempted to use your drinking water hose for other clean-down tasks.
  5. Use an inline or tap filter.

Treatment options

As I covered in my previous guide, there are several water treatment options. The most common methods are:

  1. Chemical (the only method that can be used in tank)
  2. Filtration (prior to drinking)
  3. Boiling (prior to drinking)
  4. UV (prior to drinking)

Chemical treatment in tank, combined with filtration, is most commonly used in RVs. Read about the pros and cons of each method in the guide. While not the subject of this guide, don’t forget to stop your grey water from turning into black water. Read my guide on greywater.

Stop your water tasting like crap with a cordial flavour

Fixing the taste

Sometimes, in spite of multiple rounds and methods of water treatment, you’re still left with an unpleasant plastic taste. You may have heard the old wives’ tale – a bottle of Cottee’s cordial (has to be raspberry!) or vanilla essence through the system will fix it. And the truth is – it at the very least masks it with something more pleasant.

Crap water, ready for a lay off at home

Tips for RV tank layoff

Every good trip must come to an end – and when it does don’t forget to prepare the tank and your RV for the extended layoff period. Otherwise, the next time you go to use it, it might be downright feral! There are two schools of thought:

  • Have the tank completely full of trusted potable water with no air gaps.
  • Drain and dry it out.

Personally, I’m far more comfortable with draining and drying out the tank. If there’s no water, nothing will grow. Here’s how to go about it:

  1. Fill with trusted water and add a chemical water treatment. Hold for the recommended amount of time, then open all taps in the RV until no more water comes out.
  2. Let out the drain plugs. Park the rig on many angles (consider driving up on ramps) to get all of the water out of the tank. You want it dry and stored out of sunlight as any leftover water combined with sunlight is likely to promote algal growth.
  3. Once dry, ensure any breathers are sealed off and drain plugs are back in.
  4. Don’t forget to treat and dry peripherals such as hoses.
  5. For your next trip, follow the same steps for new tank prep to bring your tank and RV out of hibernation and flush the whole system through.

Hopefully, the tips in this guide will help you stop your water ever tasting like crap! Tell us your favourite tip for ensuring fresh, clean drinking water on the road.

Words Juliette Remfrey, Images various/RV Daily.




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