Need opinions on watermakers for a specific scenario please

[bcboomer]

Originally Posted by Quadrille in JB

We have had a SeaWater Pro (20 gph-120v) for 3 years now and it works flawlessly running off of our Asae 2kw inverter. It’s not as efficient as some but the manufacturer’s support and low initial cost more than make up for it.
We run it for about 45 minutes a day as the Admiral likes her post swim rinses and a nice shower with hair washing each evening.

I'm leaning towards this system too.
Any reason you didn't buy their 12 volt version?

[Marathon1150]

Originally Posted by mitiempo

Look at the Spectra Cape Horn. Has 2 pumps that when both run give 50 gallons/hour @ 19 amps. Run one pump - either one - and get about 7 1/2 gallons @ 9.5 amps. Totally manual and very reliable. Built in redundancy with the 2 pumps. Works out to 16 watts/gallon.
https://www.spectrawatermakers.com/u...rn-extreme-330

I have a Spectra 380C which is similar but older.

We have had a Spectra 150 for about 5 years. It has worked flawlessly, sips power and makes very good water consistently. We have about 440 W of solar and a bit less from wind. No generator and no inverter. The 2 4D Lifeline AGMs store about 420ah of power. We have never had to start the engine to make power to run the watermaker except on one occasion when we inadvertently left the pressure water on while crossing to the South Pacific and a hose clamp failed at about 2AM, draining much of our freshwater supply while we figured out what the problem was. Boat noise initially masked the sound of the bilge pump so the on watch crew didn't hear it and the off watch crew were sufficiently sound asleep that they didn't hear it either. The bilge pump kept the water below the level of the high bilge water alarm sensor which is connected to a Volkswagen horn. The latter would have alerted everyone.

I quote from previous post because if I were doing this again, I would buy the Cape Horn version as suggested. The greater water production without a huge additional power demand, plus the redundancy of a second pump (most likely to fail component in the system) is attractive.

[RickG]

We have a Rainman Mk II and run it on a Honda generator or our 3000W inverter making 35+ gallons per hour. It is a compromise and I would fit a Spectra for long distance cruising. We have 150 gallons of tankage in two tanks and use 15 gallons per day when doing laundry, 10 gallons per day without laundry for two of us.

Why not buy a 12V unit like a Spectra? Our mooring is in a high nutrient bay bordered by mangroves and the particulates are quite high. We move to a nearby clear water bay to make water in the St. John, VI National Park with no overnight mooring. Making water fast every 2-3 weeks works for us.

When we summer in Grenada and have tons of extra solar I wish for a quiet 12V unit! Of course, they are twice the cost of the Rainman.

Cheers, RickG

[garychurch]

Sailboaters are amazing. Don’t know how you do so much with so little fresh water used on a daily basis.

Our daily water consumption can easily run 50 gallons a day.

[tradrockrat]

Originally Posted by garychurch

Sailboaters are amazing. Don’t know how you do so much with so little fresh water used on a daily basis.

Our daily water consumption can easily run 50 gallons a day.

We replace 30 gallons a day with rum...

[patja]

You can run the Rainman portable 115v model from a 2000 watt inverter (barely) or 3000 watt inverter easily. 37 gallons per hour, and you can run it in portable mode for a year while you figure out the optimal installation. Run it while the alternator is running, and/or go with LFP batteries to soak up the big hit and take a high charge acceptance rate to quickly recharge.

[Sailmonkey]

Originally Posted by garychurch

Sailboaters are amazing. Don’t know how you do so much with so little fresh water used on a daily basis.



Our daily water consumption can easily run 50 gallons a day.

!!!! That’s our entire tank!!!!

[pk999]

Hi, some 10 years ago we went though the same thought process re watermakers. Your 80galls tank is not large, and for frequent swims, and wash offs at anchor, (particularly if you have guests) you may use almost a tank a day. This means the watermaker will be used often. We have 400w solar, on our boat, and find that on passage, it does not provide sufficient power input to run freezers, fridge etc. (all our lights are LED), as well as nav. equipment and autopilot (one of the biggest users) - particularly if there is some partial cloud cover. Even if full sun, quite often the panels are tilted away from the sun, if on the wrong tack, or shaded by the mainsail. Our house battery bank is >650 Ahrs. but we are careful not to discharge too much without re-charging, as this greatly shortens battery life. I also fitted a Sterling Alternator to battery unit, which tricks the alternator into thinking the batteries are flat, so max. charge rate is obtained when resorting to engine.

So re watermakers: two options exist either an electric watermaker that will be on for a lot of time (your energy budget will be critical) where low gph are typical, to reduce amps draw, or an engine driven watermaker which commonly can make up to 50 gals per hour.

We went for the engine driven option, and find that 30 mins extra engine after pulling up the anchor when cruising, or when arriving at the next anchorage, will provide a tank top up. Again, with only 80 gals, you will need to keep your tank fully topped up on any crossing in the event of a watermaker failure. If you think engine driven could work for you, I suggest you check out Echotech watermakers. One key benefit of these is that they are simple, and very reliable. We have had ours in service for 10 years now, and have never had a problem, and are still on the RO original filters (obviously the pre-filters are changed each year). Recommend you check out spares availability for your intended cruising range for whatever system you decide upon. We would never now consider a cruising boat without a watermaker onboard...

Hope this is of some use.
Regards, PK

[OneKoolCat]

I have 2 teenage girls in addition to my wife so there are times we blow past 50 gpd. I made my own water maker (Similar to what you would get from a Cruise Water RO or a Sea Water Pro). I don't have a generator but i have plenty of solar and a large battery bank. I produce ~ 44 gallons an hour at around 1400W after the inverter losses. I have Victron Multiplus 12v/3000watt inverter so about 32 watts to make a gallon. Nowhere near the efficiency of a Spectra.

I try and make water in the morning. That way if I am motoring or I have some sun I am making power through the day. Most days I have full batteries by the time the sun is dipping lower.

I think that almost any system you get you will be able to make work in your setup. Try and run the watermaker at least once a week to keep things running smoothly or use an automated (or manual) flush and you will be fine.

Wait! You guys have rum makers !!??

[FlyingScot]

Originally Posted by tradrockrat

Hi all -

So we're looking at a watermaker that runs on 12V, or is efficient enough to run on our 3000W inverter (does that even exist?), can provide water for 3 crew on an ocean crossing, and keep 80 gallons toped up in remote locations around the world...and yeah, money ...It's gonna cost, but maybe we can not spend a bajillion boat units on it?

We average 100L/day for two of us. Conserve water, but obviously not as much as many others here.

Making water is a huge energy expenditure on a boat. Previous owner bought EchoTec 12v 50 liters/hr and pulls around 38 amps with the booster pump, dual filters (20um and 50um) and mineral cartridge.

How many amp hours do you think you'll make in an average day? Wind barely makes anything below a steady 10 kts. Shifty apparent winds will cut wind harvest way down from my understanding. I don't own one, but always think about having one. We have 1440wp solar and still want for more power. Your 3000watt inverter will quickly overwhelm your daily average production if used to its potential.

Buy the most efficient one available, Spectra Cape Horn Extreme would be my choice.

[izzyforreal]

We also have an EchoTec engine driven watermaker. 40 GPH and very reliable. We only have a 48 gal water tank, but we don't drink out of the tank, so I fill bottles from the sample tap before filling the tank.

Mark D
Tartan 40 Sister Moon

[David B]

Originally Posted by tradrockrat

Hi all -

I've got a specific set of parameters I want for my energy provision and I'm now researching watermakers. I'd love your opinions.

Boat: Tayana 37

Normal crew: 2 adults- wife and myself, but may often have a third crew during crossings - need water for all of us.

Water tank size - will be installing new 80 gallon tank - old tank was removed and previous owner installed a small 30 gallon thing. it looks like 80 gallons is the most I can put there without fabricating a custom tank ($$$) which only gets me 10 more gallons.

Energy provisions: regular alternator (might switch to high output), 400 watt wind generator, 400 watts solar, will be installing 4 AGM batteries for house, and one deep cell for Starter/motor.

We do not want a generator on our boat if at all possible for multiple personal reasons. We're hoping for no gasoline powered anything on our boat - even the tender will have an electric motor if we can swing it.

So we're looking at a watermaker that runs on 12V, or is efficient enough to run on our 3000W inverter (does that even exist?), can provide water for 3 crew on an ocean crossing, and keep 80 gallons toped up in remote locations around the world...and yeah, money ...It's gonna cost, but maybe we can not spend a bajillion boat units on it?

Yeah - I want a unicorn, but help me find what's out there? Personal experience with your unit would be welcomed. Thanks in advance all!

Desalator is another to look at. They also have dual voltage versions.

They are not the quietest, but are simple and reliable.

[nfbr]

PM me if you want my spreadsheet

Energy Recovery uses least power / highest cost to buy

Spreadsheet compared what if I spent extra money on solar instead, and cheaper watermaker

Depending on your water use qty - this is cheaper and simpler

Spreadsheet can compare your situation

I will say - automatic could be nice, maybe

[Dr.No]

Tradrockrat, I, currently, have a 24 volt Spectra Cape Horn extreme enroute from Halden Marine in Ft. Lauderdale. JT there has been very helpful with a few questions about installation, and I expect after the sale service to be exceptional. The Cape Horn seemed like the best fit for my needs. Having the watermaker will change some of the use of the boat. The head now gets it's input from a separate 15 gallon freshwater tank. That eliminates one seacock. This separate tank eliminates any possible biological contamination of the primary water tank, and I had the room for it.
Many thanks to Discovery15797 for the Spectra troubleshooting guide - that is now part of the ship's library.
At this stage, I expect to go with the six of the 4 volt Firefly Oasis batteries as a 24 volt bank. I can't justify the cost of up to nine grand more for a comparable lithium ion system. Cheers!

[sv Stella Maris]

45’ Catamran, 2,300watts solar, 800ah 12v AGM’s, Victron 3kva inverter, CruiseRO 35gal/hr 120v, 45gal/day consumption, 8 people aboard full time, no diesel genset, 2kw portable used only for big laundry days or deck washing, 184gal tankage.

Spectra is the benchmark for 12v; I would build my own though...cost is too high for me.

We built some accordion-folding-arrays with 200w flexible panels to boost the array on smaller boats and monos while at anchor. Simple MC4 connection to a single Victron MPPT. Was easily expandable to (6) panels and still stowable.

Good luck ! (but gas 2 stroke outboard all the way if you plan on cruising remote with some long dinghy trips...also charging an electric dink seems like a pain).

Unless it was easy to ‘unholster’ a lithium cell from the house bank and bring it in the dink...and then also onto an electric bike or scooter for shore, then back to the housebank to charge...that would be cool.