By Capt. Shane of SailingKYAN II

One of the most kicked around topics these days is water makers.

Over 20 years ago Water Makers were not a common discussion topic and were more often than not perceived as a luxury for the "yachties". 

Times have changed and water makers are incrementally as affordable as LifePO4 Lithium batteries. (and yes there is a Lithium Powered Water Maker on the market).

Having a Water Maker is a huge game changer for cruisers and liveaboards.

Beside the the obvious differences between "portable" and a more permanent installed system, there is also the interesting discussion of production, capacity costs & convenience.

Understanding Water Makers 101

A marine water maker uses reverse osmosis to make drinkable water. First observed in 1748 by a French Physicist experimenting with putting water through a pig's bladder; ( A wine filtering thing perhaps?), the concept sat on the shelf as a curious lab experiment for 200 years until  UCLA and Canadian Scientists made desalinated water using a crude type of membrane. Later on in the 1970's a membrane was patented that could handle the pressures needed to make water at large production rates.

Today, the world's largest RO desalination plant is in Israel 15 km from Tel Aviv, producing 165 million US gallons per day. 

In the old Gold Panning days, a similar but very crude process took place at rivers & streams, where unlimited water mixed with earth or sand was filtered through wire pans, trapping any solids,  some of which were gold nuggets. 

4 Gallons of Sea Water to make 1 Gallon Drinking Water

4:1. That's the approximate ratio of a typical reverse osmosis water maker. In other words to make 25 gallons of drinking water will require enough energy to pull 100 gallons of water at a lifting height of anywhere from 3 to 10 feet , then through a 1 micron filter, then pressurize that water to 800 P.S.I. and then push it through a very thin membrane (bladder) and have it fill the water tank with one line while discharging the used water (a brine solution) overboard with another and then repeat the process with another half gallon of production water to clean the membrane before putting it away. 

Portable

The use of the word "Portable" when it comes to water makers reminds me of the over-use of the phrase "Plug and Play".

Considering that weights of portable water makers can vary between 38 and 84 lbs.,  the word portable is all in perception. I've heard one sales person pitch that their model conforms to carry on baggage sizes, but who in their right mind has/wants 60 lbs., of carry on?

Keeping in mind the weight of going up the companionway steps and on to the deck or placing it in a safe area where it won't "plop" overboard. Reverse the steps and  pack it away when you are finished.

Power Supply

Consider if you have enough power resources to complete the production. The Sea Water Pro Portable 120 Volt water maker is one of the most efficient systems, claiming power consumption of 600 watts with capacity of 14 GPH at 78F.

Based on 25 GPH usage, power consumption would be 5-6 amps at 1.81 hours with lift and final purge. 

Using a 120 VAC Inverter with a 12 volt battery system would require approximately 55-60 ( Inverter load)  amps per hour x 1.81 Hours = 100 Amp hours. Keep in mind that production results can vary lower or higher depending on the both temperature and more importantly the mineral content of the water.

A pocket generator or fixed generator producing 120 volt would require between 5 and 6 amps draw.

Depending on your battery system and power setup, you always have options to power.

Replacement Filters

The "size" factor in Portable Water Makers means that space is limited, so the use of a single 1 micron filter in front of a small membrane is pretty much the norm for filtration.

Both Rainman and Sea Water Pro use a 2.5 x 5 inch 1 micron filter, which is half the surface area of a 2.5 x 10 filter and traps half the particle size of a 2 micron filter. So basically it traps twice as much in half the space. Physics laws will prevail here...its going to need changing more often than an installed system with a 5 and 20 micron filter.

Since the mineral content of water varies so much from place to place and run time varies with each use, keep an eye on the suction gauge of the system; make note of the suction pressure when you start with a new filter. When it gets to about 50% of new, or under 5 P.S.I. sample the water and if it tastes off then...change the filter. p.s. Always sample the water prior to filling the tank.

Expect the unexpected and plan to stock enough filters on board to get you through your journey.

In order to keep the membrane fresh and maximize its lifetime, it is important to save 2-3 quarts of your production water, for rinsing the membrane. By doing this after every use, the water will not have a chance to stagnate and grow bacteria.

What is pickling?

Ahem! Our AI picture generator didn't quite get it, but "pickling" a water maker is the process of adding  Potassium Metabisulfite whenever you plan to not use your Water Maker for an extended period. That period can depend on how often you rinse the membrane, but as a general rule two weeks without rinsing is the maximum time you should leave it without pickling.

To "pickle" the Water Maker, just add the manufacturer's recommended amount of powder or tablets to 2-3 quarts of production water in a bucket and run till near empty. This process is almost identical for an installed system. By the way, if you want to winterize the Water Maker, just add RV Potable Safe antifreeze instead of water, add "pickle" powder and run it.

Cost Comparison of Portable Versus Installed

In our opinion, an installed Water Maker (DIY)  may be the same or similar costs as a Portable. The differential is your time.  Example: We installed our system, but since we did not get paid we really can't translate that to a cost value.

If we paid for an installation, the final cost would have been much more and a true cost.

On the other hand, the only labor involved in owning a Portable Water Maker as we have pointed out in this article, is with carrying, setup and pack up.

Summary

Having a Portable Water Maker is ideal for any anyone who needs or wants a reliable water source on the go. Vacationers, Campers and Outdoors people use them as well as boaters.

For many of us, constant hydration is a key part of our mandatory health and wellness plans and a Portable Water Maker is a life saver for them.

Whatever your choice is, we hope this article has given you some more insight into Portable Water Makers.

In closing this article, we wish to thank (sarcastically) the few Social Media Influencers & You Tubers out there for spreading false narratives about it not being safe to make water in certain areas with questionable water It might make cool video footage to increase your ratings but your ignorance of Reverse Osmosis has misguided many potential users and has even dissuaded them.

It does not matter where you make water; with a good filter, a membrane and a high pressure pump you can make Reverse Osmosis water anywhere.

Thanks for reading...

Cheers