Good tasting drinking water is something you take for granted on land. On a cruising sailboat, the water on your boat may have sat in the tanks for some time, often in hot, humid climates. It most likely will grow out mold, bacteria, and algae. Something that I certainly do not want to drink or cook with.
We have 4 water tanks on Mahi, our 43 foot sailboat, which cumulatively hold about 190 gallons of water. We wanted clean, safe, drinking water on board, so decided to tackle this issue several ways:
Shock the System- This is where you use bleach to super chlorinate and kill any growth in your water tank system. You add a formula of bleach to each stainless steel tank according to size, then add water and turn on all the faucets on board the board until you smell the chlorine. Turn off faucets for a minimum of 4 hours and a maximum of 24. Drain the tanks, refill, drain again, repeat until the the water tastes chlorine free.
Our U-line ice maker presented a challenge, since we wanted to shock the lines going to it, but not through the ice maker itself. Joe engineered a solution where he installed a Y-valve in the line just under the unit, then attached clear tubing that feeds out overboard though a porthole temporarily. Once that line is shocked and drained, Joe will uninstall this set up and stow the tubing.
DIY Water Filter– Following these instructions, Joe made a handy device, called a Baja water filter, to pre-filter water before entering the boat. We pre-filter water from the dock, from the water maker, and from collecting rainwater.
Galley Under Sink Water Filter– We installed a filtration system under the galley sink. You basically buy and install a standard size canister (seen left), then add a carbon filter cartridge to it to remove impurities.
Grayl Water Press– Love my Grayl Water Travel Press. This is my last ditch back-up step if our water tastes funny. Works similar to a coffee press, but screens out 99.99% of bacteria, viruses, molds, and anything else in the water.
How We Plan to Obtain Water-The water on a cruising sailboat has to come from somewhere. We are far away from any docks, and plan to spend most our time at anchor. This means we either have to make our own water or collect what Mother Nature provides. This is what we have on Mahi:
Rainman Desalination Water Maker- This is our new watermaker we bought last month. It is a portable desalination unit, meaning it converts sea water into fresh drinking water. More info about this watermaker can be found here.
Catching Rainwater with Awning Attachment- Our new awning, under construction now, will also serve as our rain catcher. You simply divert the rain to your water tanks being creative with hoses and the Baja water filter to screen out any debris before the water goes into the tank. I will show you how this works when it is completed.
For more information, Practical Sailor magazine wrote a series of articles on this topic in their June, July and August 2015 issues.