Motorhome water system

Are you able to fill the fresh water with a watering can, rather than a hose. If so you can measure it.

You can find most things online. It’s 45 litres according to this on a 2007 model. That's unusual as MHs generally have a bigger fresh tank than waste tank.

https://www.outandaboutlive.co.uk/motorhomes/buyers-guide/motorhomes/details/130/10854

I will have a go at filling it up from empty -try and work out how many containers it takes to fill it. 
I did try to search online but didn’t find an answer. 
This discussion group is really helpful though. 

Hello and welcome

Just a word of warning regarding sterilising. There is at least one thread on here, possibly more!, I'd rather look for a needle in haystack than search this site - but Google could be your friend, I'm a bit time limited at present.....

Some sterilisation can damage heating and filters. 

Do you really need go sterilise? We never did ours, I don't do indoors either!

If you're worried about the water from the taps you can boil it before use, even for teeth brushing. We never had a problem our motorhome was 3 years old when we got it.  You can just fill up with fresh water and run all the taps to flush it through. You could even keep the hose on as you do. We are lucky enough to have plentiful cheap safe water on tap. I don't advocate wasting water, you could direct the 'used' water onto growing plants....

We use puriclean which is non corrosive and there maybe advice on their web site or elsewhere so that you can make a "good guess" about the amount needed.

I would suggest your fresh water tank is slightly more than your 45 litre waste.

My waste is 105, fresh is 120 & I reckon the other 15 is factored in for the toilet holding tank.

If you calculated 60 litres, regardless if it was slightly more I'm sure the solution would do some good.....

As has been mentioned previously, use Puriclean as other sterilizing agents can harm hot water elements/boilers.

hth