Looking for a watermaker

[geoffgroves]

Looking for a watermaker

I am looking at getting a watermaker, my requirements are:

• minimum 20L(5gal)/hr
• needs to produce drinkable water
• low maintenance

Any suggests would be appreciated.

Geoff

[Jsta_Rebel]

Geoff,

There are some other things you need to consider when looking for a watermaker.

What power source are you going to use to power the pressure pump? There are few different designs available including 120V, 12/24V, hydraulic, and even positive displacement piston pumps that run off of a PTO from a generator, or even off of the boats main engine.

I prefer to power off of the main engine as it allows me to use larger membranes and make more water (1.5-2.0 GPM) without worrying about the amps. The low voltage DC pumps are only used with the smaller production systems and I have found them not to be as reliable as the 120V systems. Dont get me wrong, the 12/24V RO systems work ok, but the pumps dont last or perform like the 120V, or the PTO style pumps.

One misconception is that there are "low maintenance" watermakers, and I will tell you that ALL RO systems require maintenance and how you take care of it will directly reflect the water quality, water quanity, and life of your watermaker.

I read a post from a gentlemen that only uses his watermaker when he is in crystal clear water. This is a great rule of thumb unless you want to invest in a SDI (silt density index) test kit to insure you are not "fouling" your systems membrane (RO filter) with poor quality feed water. The pre-filter on the systems only filter down to 5 or 1 microns while the RO membrane filters down to below 0.001 microns. Water containing a lot of particles lower than 5 or 1 microns can easily plug or foul the membrane. It is most important that you check your pre-filter at least monthly on a liveaboard and change it when the inside center core of the filter shows ANY discoloration.

Next is RO membrane care. It is so easy to set your watermaker up to flush itself with purified water that I can not understand why every watermaker owner doesnt do it. This little thing can extend your membranes life by two or three years over those that dont. Some systems have this feature built in, but it is costly, and setting it up consists of two simple valves, and five minutes of your time after filling your tanks.

Concentrate / Reject flow (system discharge water) needs to be checked regularly as well. The heart of your watermaker is the RO membrane, and it is basicly an artificial kidney. It needs to discharge 2.5 - 3 gallons for every gallon of water produced. Improper discharge rates will kill a system faster than any other thing and if equiped with an orifice valve to control this function remember that the orifice can become plugged and needs to be checked and cleaned regularly.

When choosing a watermaker, I always recommend that the simple systems make the best systems. Make sure that your system has a TDS (total desolved solids) monitor, concentrate flow meter, permeate ( purified water) flow meter, and a low water pressure system shut down. The rest of the bells and whistles on them are meaningless.

Hope this helps, and feel free to ask me anything regarding water treatment systems.

Jsta_Rebel

[sv_makai]

e have a SK 6 gal/hr model that is 12 volt and runs off our solar and battries with no problem. We do want to upgrade to a 20 gph model. We have been using ours for 2 years and the biggest maintenae item is using it every other day.

A big killer of WM is ocassional use. WM liked to be used.

The downside to engine driven is the cost of the fuel and the addiional time on the engine. We just got in from the Gulfo e Caricao in Ven where we stayed a month. We started the engine 3 times and that was to move the boat. We go for a week without running the engines. The watermaker supported by our house and solar system out-weighed the need to run the engine just to make water. If you boat requires frequent use of the engine and engine drive is great.

The point eing is that you need to determine what the need is, a cruiser, live aboard, weekend sail in the US or out of the country. We never used our WM in the US. Water was cheap and easy.

In the Out islands of Venezuela there is no water. We take showers, wash clothes in the washer, and do dishes only in fresh water....Spend some time determine you uses and requirements.

We love our SK and many we know love the Echo marine, both price and quality.

[Ram]

Hi Bill

Can I ask why you want to up grade to such a big jump from a 6gph WM to a 20 Gph water maker, I to will buy one this year and would have though the smaller one would be fine?

[sv_makai]

Let me set the stage a bit. When we sail or passage make we shower, we use a washing machine, and do all of our dishes in fresh water. Many people are good a minamal use. We decided we were not camping but living a life style that we feel is comfortable. Hence we use more water rather than less.

When I first set up the water maker I estimated usage and found the 6 gph to fit our needs (and budget). It works perfect and we would be comfortable using until we get back to the US in a year or so. It works and meets the needs.

Why we want to increase.

We can run the water maker for 1-2 hours every other a day or so and meet our needs rather than 4-5 hours for the same output.

Any degridation in water flow, water temp, filter condtion, sunlight (solar) and reduce the out put. 1-2 gallons and hour from a 6 gph is a lot. Where as 25 percent from a 20 gph still gets us 15 gallons. A large time reduction allows us to run it during the highest output period of our solar panels and would let us keep the batteries toppped up.

We actually throw away a fair amount of solar production s we are fully charged by 10 AM. This results in 28-32 amps per hour from 10 to about 2-3 that just get turned into heat rather than useful production.

We don't leave the boat while the WM is running so we are tied to the boats for a period everyother day. Rather be swimming!

Cost. The jump for 10-15gph is not that much greater at 20.

We love our 6gph SK watermaker, but we really like having all the water, pig-ish showers and washing the sheets and towels, when we are out island.

[geoffgroves]

Thanks Jsta_Rebel and Bil. I appreciate the help.

[Strygaldwir]

Bil;

You say you take regular showers? Do you use hot water for your showers? We have an AC/Engine water heater and I currenlty only have the water heater wired to shore power AC. When we have been cruising, we would run the engine at least once a day, so there was always hot water available. We have not done extensive anchor, but we plan to do so. I don't want to run my engines for anything except emergencies and moving, when I have to. You say you have excess power from solar panels, does this include generating power for heating water?

Thanks again,

Keith

[sv_makai]

Certainly that is one option, but we use hot water for showers, washing dishes, etc and we like things on demand. We don't like things laying around on deck and chose to build in all of the equipment so that it doesn't appear to be just added on as an after thought.

But that is just us.

[bob46777]

After looking at every watermaker on the market and getting sticker shock I decided to build my own. I have just completed a 12 volt DC watermaker for my second boat. Both plans are on ebay under watermaker

[44'cruisingcat]

Re hot water while at anchor. One alternative - Hot Water Systems - Northcoach Equipment

[Pblais]

Bosch makes a ventless propane on demand hot water heater. It will run as long as you have propane. No hot water tank at all. The on demand nature of it is nice and it it is very lean on propane use. Even very cold water comes out hotter than you can shower with.

[44'cruisingcat]

Originally Posted by Pblais

Bosch makes a ventless propane on demand hot water heater. It will run as long as you have propane. No hot water tank at all. The on demand nature of it is nice and it it is very lean on propane use. Even very cold water comes out hotter than you can shower with.

Ventless? That sounds good, but what about CO / CO2 buildup?

[Whimsical]

It has a CO and oxygen depletion sensor which will shut it down if needed.
It sounds ideal and is on my list.
Mike

[44'cruisingcat]

Does it have a pilot light or ignition on demand?

[mickmul]

Hydrovane ( the vane steering company) are now doing a range of watermakers - I can't vouch for them but I reckon they wouldn't cheapen the vane brand by taking on anything less than excellent. Self Steering - Hydrovane Selfsteer if you want to check out the specs . . .