At the risk of starting a debate, we are also in the "bonkers" group! The "fresh" water tank never empties fully, just topped up....
then why not empty it..its not a big job to drain the system after every use and flush before the next...plus occasionally sterilize the system, when space is at such a premium why waste it carrying the same thing twice...?
Our water system both hot and cold gets a sterilizing at the start of the season and is always used for boiling the kettle for hot drinks.
Always drain both fresh and grey water tanks before the return journey though.
I am expecting great things though when we empty the grey tank this time. We have had a couple of dishwasher tablets (dissolved in boiling water)sat in there for a week and when we drive off to come home it will get a good sloshing about as we drive to the disposal site and lots of gunge (if any) will be dislodged ready for any build up that may occur.
I will report back on what if any difference it makes to the fuel useage.
Thanks for your help in this dilemma - fuel v time is always a close run thing!
Where do you think mains water is stored? its in the pipes in the ground for quite a while, and if you have ever seen inside of an underground water pipe you would never drink it again!
Perhaps those who choose to arrive on site with a full tank of water on board could ask the site owner for a discount on the pitch fee, after all that is calculated into the cost of the pitch LOL.
As for taking up space, a 2 litre bottle of fresh water doesn't take up much. I drain and flush the grey water tank after each trip, but the fresh water only gets the treatment once a year (over winter).
------------- Two drifters off to see the world.
I'm tired of reality, so I'm off to look for a good fantasy.
Back from our jaunt - DH says it has made very little difference to the amount of fuel we have used so for a weekend away we will repeat the exercise.
One thing it has done is removed any remaining sterilizing sediment that was lurking in the bottom of the tank. Left us with water that tasted like TCP all weekend - for the first time we had to buy bottled water for our tea and coffee
I know everyone is going to say you should rinse out your system after steralising and we do - twice but there must have been powder in the bottom or something cos it tasted rank!
Never mind - that tank is very clean now and before we use it again it will have a trip to the garage for filling up with fuel before then and the fresh water tank will have some water in it to flush out anything that may be left. Already been filled and drained since we got back.
Oh yes - the grey water tank - not sure if it was a bit muddier looking but that might have dislodged something from the bottom of the tank. Maybe the grey tank wasn't that bad after all.