The water system we use has evolved over the years. We started with a very simple system: fresh water tanks, pump, accumulator, water tap and grey water tank. One year later I added the hot water supply, combined with an engine heater, the Eberspacher D4WSC. After that it made sense to create an extra water tap for the shower.
Then, in the course of three years, I experimented with several types of in-line filters. The need for a good filter was not so high, because the countries we visited had acceptable drinking water, and occasionally we used bottled water. However, thinking about overlanding, a better (filtration) and easily serviceable water filter system would be preferred. the water filters used should be available worldwide. In the end, this meant that I used standard 5″ and 10″ filter cannisters. These are used in residential homes as well as yachting, making it easier to obtain filters.
If we find clean water
If the water is of good (trustworthy) quality, we drop it straight in the tanks and add a drop of Hadex to reduce algae growth and has a moderate effect to kill Protozoa and a high effect to kill bacteria and viruses. Next, the water will go trough a mesh filter to protect the pump membrane, then it will go trough a 5″ active carbon filter to remove chlorine, and remove (or at least reduce) pesticides herbicides, nitrate, PFOS (a synthetic chemical used in e.g. fire-fighting foam), lithium, and pharmaceuticals. Finally it will come out the water tap.
If the water is doubtful
In this case we can use an optional 10″ <1 micron ceramic filter to clean the water before it enters the tank. Usually in this situation a filter system is used: a sediment filter would be used to protect the micron filter from clogging up to quickly. We just don’t have the space to use this extra filter. We solve this by wrapping a coarse filter around the submersible pump we use. Doubtful water will be sucked from a collection point where the coarse filtering takes place, then it will go through the micron filter to filter out protozoa and bacteria. Again the Hadex will kill viruses. As mentioned, a possible drawback with our system is premature clogging of the micron filter. It is counteracted by the fact that it is 10″ in size. It is also possible to carefully clean the ceramic filter by hand. So we can use it longer.
If starting from scratch, I would advise to buy the required filters also before starting the build. I did not, thinking that enough room was reserved, but time would tell otherwise.