Cleaning Not Equal to Sanitizing

We decided to clean our fresh water tank.  I found an article on the Canadian Doulton (of RIO 2000 from the South of the Border filtration system fame) that described cleaning before sanitizing.  The point made in the article was that sanitizing does not equal cleaning.  In a continuation of our filtration/purification theme, before we left our last Thousand Trails at Wilderness Lakes we opted to follow these instructions.

How to clean the tank

First up was how to clean the tank.  This seemed simple…a ratio of liquid soap to water, run about 20 gallons into the gray tank for extra sloshing fun, then drive to generate said sloshing, run the water at the end to drain the tank.  Simple.

Cleaning the tank does a few things for us.  First, it gets rid of scum and other dirt that might have deposited, mostly in your pipes.  Secondly, cleaning will neutralize any oily buildups, mostly in your drains into the gray tank, but hey, we’ll call this one a bonus. And thirdly, it gets rid of any slime that may have accumulated over time as a by product of bacterial growth.

Yeah.  Think about that for a moment…your freshwater tank could be home to slimy poop from bacteria.


To clean the tank, the instructions were to add 4 teaspoons of liquid soap for every 10 gallons of fresh tank capacity.  We have a 100 gallon tank, so 40 teaspoons it is.  After a Google conversion to ounces, our magic number was 6 2/3 ounces for a 100 gallon fresh tank.  So, what did I do?  I decided that the whole 8 ounce bottle would be fine…it’s only just a little over an ounce more, what could go wrong?


Lots and lots of foam.

We are still pumping soapy water.  Our second 100 gallons is going through it as we speak.  The foam is much less now, though not completely gone.  So, note to self…FOLLOW THE DIRECTIONS TO THE LETTER!

The next stage in the process is sanitation.  I’ll post about that once we get through it later this week.

Special NOTE

This is a water intensive operation.  I’m typically quite sensitive to water usage and I try to be as conservational as I can be.  But, I also have to weigh the safety of our water supply for the humans AND for the pets we travel with.  This process is only needed every 3 months, but, wow.  We’re using 200+ gallons of water to just clean it.  Sanitizing will likely also take about 200 gallons.

My advice is to pick your location wisely so as not to tax the local water system.  I’m prepping for 12 days of boondocking and want to be sure our onboard water is clean and safe.