What we have learnt about using and storing water on our boat.
Part 1 storing water on our boat
On our first boat, Lupari, we had water in 2 x20 litre jerry jugs for use in the galley. These were easily taken out and refilled. In the head we had a 50 litre water bladder and used hand pumps on the sinks. Because we were not sure of the quality of the inside of this bladder we were not prepared to drink it. We were never confident, no matter how hard we cleaned it that it was good enough for drinking water. It was perfect for the head, for bathing, for dishwashing water and teeth cleaning etc. But we were never able to go too far away from water. While we were l cruising up around the coast it was not a problem. We kept another jerry jug for collecting water from other sources, waterfalls, rain etc for laundry and as back up to our head water. We installed a salt water pump in the galley for washing up, washing hands, rinsing vegetables etc. Salt water in the galley was a great idea and helped us conserve our drinking water. This helped save our drinking water but killed the engine... but that is another story and one I am not qualified to tell
On our current boat, Lupari2, when we first took possession of her, she had approx 300l galvanized water tank, 20+ years old, plumbed to the galley and the head. It kept us in water on our coastal cruises and weekends away. We had enough to use for washing and we were always able to top up with clean fresh water when we returned to the marina or boat club. We also caught rainwater from our bimini. After a few months we began to notice red sludge in the drinking water if we had been out on a rough day, so we installed a particle filter in the drinking line to filter out all the dirt, thinking that it was just accumulation over several years. Before long it was getting through this filter as well. After crossing Bass Strait, we decided to investigate the problem and try and fix it once and for all.
The first task was to try and get to the tank which was not an easy job .( note to self...make access to inspect tanks easy)When we cut through the tank we noticed large black muddy bubbles on the inside of the tank and rusty mud oozing from them. Here was our problem. After 20+ years in water, galvanizing does not last. The steel tank had rusted and was in danger of rusting through so we cut it out. It was winter in Melbourne and we were keen to get to warmer places. The cheapest, most efficient and time effective thing we could do at the time was get 2 x 80 litre caravan tanks from a caravan shop and install these in its place in the engine bay. This cut our water capacity by half or more. But we did have room for a few 20 litre drums as well. The water coming from this new tank tasted awful. The plastic taste permeated everything, so as well as the sediment filter, which we kept in the plumbing system, we added a dedicated drinking water tap which was fed off the original plumbing and we put a carbon filter on the line, we later exchanged this for a ceramic filter which we could clean with a Scotchbrite scrubber, cutting down on waste that we had to dispose of. This allowed us to have lovely fresh clean water that we could drink. We added a deck fitting to fill up from outside. Everything worked well. We used these tanks for several years (5); coastal cruising along the East coast of Australia while preparing the boat for passages further offshore in the future. For general use they used to last us about 2 weeks excluding laundry.
That is 160 litres for 2 people for 2 weeks.