Cracked nylon thru-hulls are a common problem, as a walk in almost any boatyard will bear out. Unlike fittings constructed of industry approved materials (bronze, Marelon, etc.) nylon thru-hulls are not recommended for use at or below the waterline. Age often plays a factor in the failure of nylon thru-hulls, but ultraviolet light is the main culprit. While different brands vary widely in their susceptibility to UV damage, some are so poorly made they can fail within the first year of use. The stress placed on the thru-hull by an unsupported hose can also cause failure, with the weight of the hose acting like a lever as the boat bounces around while underway.
When testers dismantled Practical Sailors test holding tanks-the site of years of experiments with holding-tank chemicals, sanitation hoses, and vent filters-we hoped that it was the last hands-on contact wed have with marine sanitation systems for a long time. And then a friend came to us seeking advice on curing his regularly clogged head. He had checked the obvious culprits-scale buildup in the hoses, blocked vent, etc.-and found everything in proper order.
Pulling hoses is generally low on the fun list. They are in bad places, jammed onto crusty hose-fitting barbs, and have stiffened over the years. As part of our 2016 update on long-term tests, we needed to wiggle loose a few of the sanitation hoses were testing to see how they were looking on the inside-a job much less pleasant than new installation.
If youve followed the first two installments in this three-part series on ensuring safe, fresh-tasting drinking water onboard, youve cleaned your freshwater tank, pre-filtered all water going into the tank, screened the vent, and disinfected the contents. Now that the water has sat in the tank, its time for one more filtration process; this time, focusing on improving taste and eliminating micro-organisms.
Only a few states require National Sanitation Foundation (NSF) certification for water filters, and the requirement applies only to a small number of original equipment manufactured (OEM) products.
In the first part of our three-part series covering onboard water quality, we discussed protecting the tank with basic filtration and securing the tank vent. Further action is required, however, as the tank and its contents will always be far from sterile. Municipal water is filtered to remove turbidity, disinfected (typically with chlorine, ozone, or ultraviolet light), filtered once more (often very fine filtration to remove cryptosporidium cysts, which resist disinfection), and disinfected once more (with chlorine or chloramine) to protect the water while its in the distribution system. However, since we are storing the water on our boats, this process of secondary disinfection becomes our responsibility. So what are the options for treating water that is already in an onboard tank?
Foul tank water is completely preventable. Here are some dos and don'ts for a healthy water tank. Dont place glycol or other winterizing agents in the tank. Install valves as needed to winterize the pipes only; typically a tee and two valves located near the tank drain work fine.
Leave water from any source in a storage tank for a while, and interesting things will start to grow. Only the purest water in an airtight bottle will have a long shelf life. But not all bottled water is what the label says it is. For a cruiser, there are two water-testing tools that are important, and a third tool that is helpful in determining what is going into a tank and managing the quality of fresh water on a long-range cruising boat.
You would think that with all the emphasis cruising sailors put on their boats and equipment, we would pay a little more attention to ensuring a clean and safe supply of water. This is less a concern in developed countries, where dockside water is safely treated or bottled water is affordable and readily available. However, once you begin to expand your horizons, ensuring a clean water supply requires more thought and effort. This is the first report in a three-part series on equipment and practices that no matter where you and your boat are, you can be reasonably sure that your on-board water supply is safe.
Water filtration isn't rocket science, but some filter media is better suited for the marine environment than others. And, as we found in our test, some cartridge designs are better than others. Here are the most common types.