The Result of Winterizing My Fresh Water System

When I winterized my fresh water system last fall, a few people told me not to put any anti-freeze in the fresh water holding tank as it would leave a bad taste. Well, I never drink from the tank and I had a theory, so I decided to do it anyway. Here’s a shot of my tank last fall:

Notice that dark band at the bottom? You would be incorrect in thinking that it is simply the anti-freeze showing through the tank. The anti-freeze was not that dark. That dark band has been there since I can remember and all my clear lines were that colour. That black stuff is fungus and the reason why my water has always smelled musty. I tried to shock my system a number of times with bleach, but I could never get rid of those spore sgrowing in my fresh water system. I eventually figured out that I need to live off my holding tank rather than connecting to city water, but by that point the infestation was pretty severe.

My theory last fall was that letting my fresh water system, including the holding tank, soak in anti-freeze for six months would kill off everything living in it.

This is what my fresh water holding tank looks like now:

I have never, not even when I first started traveling, seen it so clear.

I feel that I made the right decision putting the anti-freeze through the whole system. I gave the fresh water system a good flush before leaving Lethbridge. There was a whiff of an anti-freeze smell while on my first holding tank of water, but now that I have refilled it a couple of times, all I get is clear water that I have actually felt comfortable brushing my teeth with. I’d call that an improvement!

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  • Hmmm. Interesting technique. I must remember it since I’m about to become a part-timer who won’t always be living off my tank. Thanks.

  • I think that shows why you would not want to ingest the antifreeze in any way – if can kill fungus spores. I wonder if a strong bleach solution would have done the same over the same time period. Fungus can be extremely hard to kill. The 6 months of sitting had to have helped kill it. Shorter periods would probably not have worked (like a few hours as in most shocking).

    Good it killed the fungus. I bet, with better management, you will not need to repeat the long antifreeze treatment again.

  • Rae – as part of the cleaning of your water system, the use of bleach is bang on. As you flush it out prior to preparing your tank/lines for drinking water, don’t forget to remove the aerator screens on your taps (and soak them in bleach) – they often trap remnants of the black fungus….. Best of luck in your travels


  • Rae – in addition to my last comment, also clean and soak the screen on your water pump – you might find “stuff” growing there too!


  • Tesaje, the antifreeze is potable, so I’m pretty sure it’s safer than fungus. I will only need to use anti-freeze again if I have to winterize the rig again. 🙂

    Mike, thanks for those tips. I did do the pump but missed the aerator on the taps!

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