How often do you clean your freshwater tank?

Sounds like you know your stuff, Marksailor!!!

We gave up using an aquaroll after discovering the mess in the pump and pipes which are in my photo earlier in this thread, and now keep only a small container of fresh water in the van.  We prefer to fill our kettle and cook vegetables with water directly from the site tap and we prefer to use site facilities for showering, washing up, etc.  

We use bottled water for the first couple of days of a trip, but after that dont really bother too much, thinking that any nasties will have been flushed through by then. Been doing it that way for over 30 years and the system hasnt let us down yet.  Our aquaroll must be over 20 years old. We had a smaller version first and purchased the 40 litre one as soon as they came out, so its pretty old now - like us!

TF

 .... so its pretty old now - like us!

TF

Would it last THAT long ........ 

Indupitably!

TF

If you are really paranoid about it you could always try using what a lot of home brewers including me use.  Which is laundry bleach like vanish, however don't buy vanish because it is perfumed but the cheaper versions available for lidl or Wilko's is not perfumed and much cheaper and it does shift dirt and is not afaik harmful to stainless steel. 

Oxygen based laundry bleaches (like Vanish) are not good enough to be recommended as disinfectants. Even with TAED, which allows oxygen to be produced at low temperatures, they don't achiveve the level of microbial reduction required for them to have a suitable effect in water systems. They also contain enzymes and detergents which, while not harmful in themselves, should not be used in potable water systems. There are oxygen based disinfection systems (as well as chlorine, silver, sulfur oxides and ammonium systems) available, but anything used on a caravan/motorhome water system must be designed for potable (drinking) water, as other systems may leave residues (or damage materials used in the system)

I realise that I didnt make myself clear.  I didn't mean to imply that oxygen based cleaners are disinfectants they are not.  When they are used in home brewing they are part of a two step process (Actually it's three steps). Cleaning ie the laundry cleaner, rinsing to get rid of it finally disinfection or sanitisation. For effectiveness you should ideally sanitise something that is already clean.  

Do I do the above in my system as I have said before no. I rely on regular use to keep the system clean enough.  In the main a few bacteria in the water from the environment won't do any harm.  The danger is almost always from a fecal source.  

You couldn't make this up.  As soon as i posted the above. I opened up the mail. Which included a copy of my companies internal magazine.  Cover picture?  A electron micrograph of Esherichia coli  cells.  You really don't want those in your water. 

ValDa, don't blame you if you had algae in the pipes. With motorhomes, you draw the fresh water from the tank through the system until it pours out of the open drain taps and kitchen/bathroom taps. Then you close all the taps, top up the water system if you want, and the water system is full of your cleaning solution. The downside is that motorhomers use a lot more water to cleanse the system. Might go back to Milton though if Puriclean leaves the algae alone - unless its a summer heat thing [we don't visit hot European countries].

 you can't get algae in the pipes because there is no direct sunlight on to the pipes, as for the hot water tank, when you switch it on it gets hot enough to kill any bacteria ive been using a aqau roll for year's and never had any algae in it, also if you drain down your caravan after it has been used every time you should never have a problem, and besides you should never drink the water straight  from the tap i have been a plumber for along time and have never come across algae in any type of pipe ive cut open plastic or copper and ive never seen any algae in hot water tank's , and before you say it ive been in void houses where the water has been off for months and guess what no algae in the pipes.

Write your comments here...

And just to add to the above all caravans are fitted with food grade water pipes these days, i see people using clear water container's which will allow algae to grow if left long enough also in old caravan's some do have clear pipes where if light does  come into contact  there might be some algae growth  because they are not of food grade qaulity as for aqua roll container's do not allow any light in for algae to grow, and if you are that worried about your aqau roll you could always put a bleach tablet in and swill it out after, and even then there will be tiny droplet's of water left over so your back to where you left off just swill your aqua rolls out when you come to use them because there is a certain amount of chlorine in the water anyway to kill any bacteria to start with  

You can get algae in the aquaroll - some algae can grow in the dark (or rather in the very small amount of light which penetrates the aquaroll from the open top under the pump rubber.  If they grow in the aquaroll they are then transferred into the pipework where they settle on the walls of the pipes along with a variety of other bacterial debris. 

We always cleaned our aquaroll each time before we used it, leaving it full for as long as possible, before flushing it through the caravan pipes and then rinsing through with clean water.  

We discovered our problem when the external pump packed up, and OH took it apart to see what was the problem.  He was horrified to find it absolutely full of this smelly greeny-black sludge, so he then removed the blue pipes which transfer the water to the aquaroll, and was even more horrified to find that the entire length of them was surfaced by this greeny-black gunge.  I suggest that anyone who has a failed water pump takes it apart to have a look at the state of the inside!

Whilst I don't want to say that everyone should do the same, I'd much rather be safe than sorry, especially as I suffered from symptoms which are thought to have been related to the toxic effects of some of these algae on the central nervous system.  Some algae are known to kill small animals, and even dogs swimming in water where there are 'algal blooms'.

I never clean the tank, the pipes or the aquaroll.

i use bottled water when away.  Tap water only for washing and teeth cleaning.

i work in a very old building with very old plumbing where there's a lot of "slow flow" spots and dead ends.  We have the water tested at work weekly and it's always positive for some really not very good bugs.  Pseudonymous, etc.  It worries me that my caravan would be the same due to extended periods where the water isn't flowing.  At home I'm happier that the pipes are in more constant use.