Watermaker for A28TE

[drbob]

Has anyone installed a watermaker in the 28TE?

Type, size, cost, issues?

We have a 2005 A28TE (engine box) with Next Gen generator.

Thanks,
Bob DeGroot
2005 A28TE
Day Tripper

[djpeewee]

We have an Aquamarine water maker and DC generator in one unit.

In one hour:
24 gallons water out to the tank
160 amp/hours DC out to the batteries
1/3 gallon of diesel in to the Kubota

We make enough water in one hour to fill our tank and charge our batteries (2 x 4D and 1 group 24) after 2 nights on the hook. We did not connect to shore power or water at all this whole season. In fact, I converted the wash down pump to fresh water and use the hell out of it.

The system is modular, so you can tuck it in where there's room.

There are a few drawbacks, but they are manageable. The main drawback is that you can no longer fill your water tank with tap water. The chlorine will kill the RO membranes. This is true with any RO based water maker.

The higher output water makers, 20+ GPH, require a good bit of power. ~1.5kw AC or ~125 amps DC when you include the boost pump and the main pressure pump. This has been the real limitation of higher output water makers on smaller boats. 125 amps DC is not sustainable for anything but a short amount of time (think running your microwave for an hour off inverter power - not happening). You do have an AC generator so the AC version would be possible. Aquamarine and others make AC motor-driven water makers. Some also make AC generator-mounted belt driven versions. I am not sure about Next Gen, but I do know that Aquamarine makes a Westerbeke mounted version.

Also, duty cycle is something to pay very close attention to when sizing a water maker. Too small, and you'll run the thing all day to meet your water needs. You can't have too big. Usually 1 - 2 hour run time what's recommended to fill the tank. There are some low power, low output (1.5GPH) water makers on the market, but you would have to run them continuously. Depends on how many people are on the boat too.

Problems? We haven't had any now that the initial installation headaches have been resolved.

Cost? Anywhere from $5k to $10k.

I was skeptical at first, but definitely love the water maker now. I just wanted just the generator piece, but the wife wanted the water maker also. I'm glad I listened to her this time.

[drbob]

Thank you for the information. That really helps. I didn't know about chlorine killing the filters.

We use the Camco TastePURE Water Filter on all water going into the tanks. Filters out chlorine, metals, sediment, bacteria, etc. so after a few tank refills, the water tastes like water should.

I think we're going to pass the watermaker. Last time we spent 3 months in the Bahamas (on our DeFever) there was always water available on the islands. Thought we'd just save a few trips to dock. So now the plan is to get a 30 gallon flexible bladder type water tank from West Marine and put it in the fish well.

Bob DeGroot
2005 A28TE (engine box)

[djpeewee]

The free chlorine tolerance is <0.1 ppm on the RO membranes. Any more and you'll be spending a few hundred dollars for a new one. Not a problem as long as you don't use tap water - ever. We don't often have access to (clean) water in the wilds around here, so the water maker is nice. Our trips would be shorter and closer to civilization without it.

[catalina_mike]

On my regal I had a backwash system that used water that was ran through a carbon filter first. I also installed a UV light on the demand pump. That way no matter how the tank was filled dock or watermaker the water was treated for virus and bacteria first before coming out the faucets.

[Jeremyvmd]

Ok I'm confused...which isn't hard to do...but from my understanding a reverse osmosis watermarker draws water from the environment desalinates/readies it for drinking and pumps it into your tank. If that's the case, how does the chlorine in the water in your tank get to the membranes to damage them?

[catalina_mike]

To prolong the life of the membrains after making water you flush them...

[Jeremyvmd]

Ahh that makes sence...thanks, I knew there had to be a simple explanation

[djpeewee]

Every time you run the water maker you need to reverse flush the system with clean tank water to get the saltwater gunk out before shutting it down. The clean water is the water you just made by running the water maker. If you have filled your tank with tap water, the chlorine from the water will enter the water maker the next time you flush the system. If I recall correctly normal tap water is treated with 2-3 ppm chlorine. As I mentioned above, the tolerance of the RO membrane is <0.1 ppm. Again, it doesn't take much to damage the membrane.