To keep or upgrade watermaker

[themorb]

Hi all, looking for some advice. We are a 49' monohull with 3 kids on board, ages 8, 10, 12 going from BC, Canada to pacific Mexico, across to Hawaii, and back home, on a one-year sabbatical. Not exactly sure what will happen after the year is done... options are keep the boat at home, keep going, upgrade to a larger boat, etc.

Researching water makers lead me to energy recovery 12v units to run off solar ie. Spectra. Turns out the Canadian Spectra dealer was right in my home town. Since they all use about the same 4 watts / litre, and people say watermakers "like to be run a lot" I calculated that the Ventura 150 at 6.3 gallons/hr should be fine. Our tanks hold 120 gallons, so it should take 20 hours to go from full to empty. We have never used anywhere close to 60 gallons in a day, so I was thinking <10 hours run time per day. Probably more like 5-8 hours.

So we bought the 150C with the touch screen fully automatic control for convenience, and I spent close to a week carefully installing it in our boat. I was told the filters should last a month+ so they are neatly installed under our bed.

What I didn't fully consider is 5-8 hours of run time outside of a harbour is kind of limiting. What if we are staying in the same anchorage for days at a time? We left Canada on August 2 and a few days later, ran the watermaker in an "open anchorage" for about 12 hours. The filter quality went from 100% to 10%. The next time I ran the watermaker, it quickly dropped to 0% and shut off. I put in new filters and the next time we ran it for about 8 hours about 10 miles offshore. They clogged up in those 8 hours.

Talking to a few Spectra experts on the phone, yes filters can clog in a day in an anchorage but even 10 miles offshore there is still enough plankton up north that it's not much different than a harbour. There is a plankton filter kit we could add, but as we are heading south they recommended not bothering with it as the plankton should subside.

Right now we are in southern Oregon, and will be in California soon where there are a bunch of Spectra dealers. Obviously I need to pick up a case of filters at minimum.

Talking to the Spectra guy in SF, there are a couple other options we could consider to increase output and shorten run time. He could rebuild our Clark pump for 10% output and turn our system into a 200C, so two extra gallons per hour. The other option is to buy a whole new system, the 340C, at double the output, and leave our 150C with him on consignment. This is quite an expensive and time consuming option, but one I am strongly considering. I also like how the 340C has a longer lasting feed pump, although I could carry a replacement pump head for ours and that would be far cheaper than a whole new system.

Say we need to run ours on average for 5-8 hours per day, so upgrading to the 340C would cut that in half to 2.5-4 hours per day. So we will still need to run "near shore" and in "clean anchorages" in Mexico. We aren't going to want to up anchor and motor way out on a calm day just to make water for hours.

So that leads me back to -- if we need to run for 4 hours in an anchorage, what difference is it running for 8 hours? It is quiet enough not to be too annoying. I believe it would be overall the same volume of water passing through the filters. So maybe I should save my money and just get used to the idea of changing filters more regularly. I will move the filters from under our bed to the other side of the bulkhead in the sail locker where they will be much more convenient to replace.

We have a Honda 2000 generator on board, and I did consider a much cheaper AC unit from CruiseRO at 30 gallons per hour, but that would mean running the generator for 2 hours per day, every day, which I am thinking would get very old very fast.

So if you have read this far, what do you think? Upgrade or keep? I would love to hear thoughts from anyone, particularly if you are cruising with kids or happen to be around the Sea of Cortez where we are headed!

Thanks!!!
Nathaniel

[markxengineerin]

We aren't going to want to up anchor and motor way out on a calm day just to make water for hours.

Yes, this is the worst. Life scheduled around an expensive device that was meant to be an upgrade to convenience of living. These are all the things they don't tell you when signing up for watermakers, and I also learned the hard way! Running every single day seems like a real pain- I run mine once a week at the most, so I would definitely think about either conserving more water as a family philosophy or perhaps upgrading to a bigger size. I feel your pain on that decision, don't know what's best.

For the pre-filter issues, mine used to clog just about every single time I used them, until someone on here told me to remove them after every use, and spray off well with fresh water, and store dry. Since I started doing that, I haven't replaced them a single time, and they're fine, all coastal waters from Florida to Maine. This tip may help you less if you're already making water daily, but might be worth a try.

[Grith]

I have also been struggling with what to buy for a 28 foot trailerable yacht planning a very remote 3/4 month expedition where water sources are very uncertain.
I will be interested to see peoples reply’s.
We do have a 1000w solar array and produce surplus 12 and 240v power on most days negating the need for generators or running engines.
We have significant ( for a tiny yacht ) 220 litres of onboard water storage and various fresh water saving techniques but a RO watermaker would be great but picking and affording the right one seems very challenging in accordance with your experience. ☹️

[markxengineerin]

Off topic, but how did you manage 1000w on a 28 footer? Photos of that would be cool to see.

Pickling I haven't found to be that big of a deal... because I never do it. The longest I've gone in between uses is about 5 weeks, more typically 1-2 weeks, and membrane has been fine. I do a thorough flush with product water if I know it will be idle for more than 24hrs. Maybe there is some risk with this method, but it has been working for me, and I've already saved the cost of a new membrane in avoided hassle of pickling.

[CarlF]

Last boat was a Spectra 18gph Newport new boat has a CruiseRO 12v 30GPH.

You are right that the same amount of water will clog the filters at the same rate. We’ve experienced plankton in Maine - most people in southern waters where filters last a month or more have no idea what it’s like. You really have to be 20+ miles offshore to get fully away from plankton.

We went to the CruiseRO because we didn’t need to spend the money for energy recovery as we have 1600 watts of solar panel (a cat). But if power is dear it’s hard to beat the Spectra - especially as you already own one.

If you are going to remain in less clear water, my suggestion would be to add the plankton filter or any other large 20 micron filter. You may need another feed pump or to adjust the Spectra pressure sensors to push water through the extra filter. The big filter will protect the other filters and hopefully won’t need to be changed as often simply because it’s bigger.

[Grith]

Originally Posted by markxengineerin

Off topic, but how did you manage 1000w on a 28 footer? Photos of that would be cool to see.
.

Apologies to the OP re watermakers but just answering a question.
720w via 4 180w thin frame light weight rigid panels three of which are removable thumbscrew attached over the rear Bimini and one on the targa bar behind this which is tiltable fore/aft also removable thumbscrew attached.
The whole package remains erected whilst towing with it being able to adjustable tilt down to allow the mast to be lowered and then carried on top.
A further panel is mounted between the handrails over the cabin roof which is a no step zone anyway.
By detaching one side this panel can be tilted port starboard.
Finally a flexible panel which mounts over the dodger when sailing and on top of the stacked and packed mainsail at anchor to improve performance.
I have a central Bimini for use in some very light and specific sailing conditions but generally folded up under the rear Bimini when more seriously sailing that is about to get further 2 foldable flexible panels further enhancing performance.

[markxengineerin]

Thanks for the pics!

To OP, what size prefilters are you using? I have a 20 then a 5, always in use. Sometimes I add a 50 micron upstream, but not usually, as it can mess up my automatic air bleed system if that one gets too plugged up.

[NYSail]

The higher output model will produce more water quicker however you are still filtering the same amount of water and will digest all the critters. The idea of rinsing the filters each time after use is a nice suggestion. A water maker is in our future and I am slowly researching. I love the thought of a dc model to feed off my solar, however I just got a small genset (3,500kw) for air conditioning when needed as well as a future water maker with the intentions of turning my rear water tank of 50 gallons into a second fuel tank. That would leave me with 100 gallons of water with the ability to fill quickly with the ac model.
Good luck!

[CarlF]

Originally Posted by NYSail

The higher output model will produce more water quicker however you are still filtering the same amount of water and will digest all the critters. The idea of rinsing the filters each time after use is a nice suggestion. A water maker is in our future and I am slowly researching. I love the thought of a dc model to feed off my solar, however I just got a small genset (3,500kw) for air conditioning when needed as well as a future water maker with the intentions of turning my rear water tank of 50 gallons into a second fuel tank. That would leave me with 100 gallons of water with the ability to fill quickly with the ac model.
Good luck!

Depending on the size of your battery bank, a DC watermaker gives you a lot more flexibility. The best time to make water is when underway because the filters last much longer - I hate listening to the genset while sailing. And you can still make water with a 12v watermaker if your genset or inverter dies.

The second choice is energy recovery (Spectra is the most common) or not energy recovery ((CruiseRO and many others). Spectra’s are double (or more ) the cost. It is often cheaper to invest that money in more solar panels and/or battery capacity. I love my CruiseRO 12 volt even though I have a genset and large inverter. .

https://www.cruiserowaterandpower.co...-water-makers/

[themorb]

Originally Posted by markxengineerin

Thanks for the pics!

To OP, what size prefilters are you using? I have a 20 then a 5, always in use. Sometimes I add a 50 micron upstream, but not usually, as it can mess up my automatic air bleed system if that one gets too plugged up.

Yes I have a 20 and then a 5 and the pair are somehow monitored by the Spectra system. I think it is measuring pressure before and after the filters. Anyway it shows remaining filter quality in percentage. I was considering a 50 micron or maybe some sort of finer mesh sea strainer… but I guess I can’t add too much restriction or the feed pump won’t like it.

[BlueH2Obound]

Not addressing replacing the water maker, but I AM addressing the filters. If your water maker used standard 10" filters, 20 micron, and 5 micron, readily available at big box stores, or on Amazon, here are a few recommendations passed on to us by Mike, the owner of SeaWaterPro water makers.

First: Buy only pleated filters. Do NOT buy the bargain basement foam or "rope wound" filters. The do not have the media area that pleated filters have, and cannot be easily back flushed to clean.

2nd: Both as a cost saving measure, and to reduce the amount of filters you need to Buy/Store/Dispose of, do the following: When a filter begins to fill up, remove and replace with your standby filters. Take the clogged/soiled filters, using a piece of plywood, or plastic, say 2" or 3" square or round, drill a 1/4" hole in the middle. Put a line through the hole, with a washer, and tie a figure 8 knot. Thread the other end of the line through the filters in need of flushing, and drag behind the boat for an hour or so. The sea water will go IN the middle of the filter, and back flush the debris back OUT of the filter. Retrieve the filters, let dry, and they now become your standby filters. You can do this multiple times, using the same filters over and over again before you need to periodically cycle brand new filters through your system. Literally "Rinse & Repeat"!

Oh, and we went one step further and installed a large, spa type filter between the raw water pump and the 20 micron filter. We flush that filter in the same manner as the above.

Note: This method of flushing does not use fresh water, and has the added benefit of more thoroughly flushing the filters. Enjoy!

[markxengineerin]

The dragging filter method is not recommended by Tellie, the local Spectra expert, because 1) if you think about it you're slowly plugging the filter with debris from the wrong side, and all that junk is going to end up in your membrane 2)he posted a story about getting jelly fish guts (or some other nasty thing) in to the membrane as a result of this method. Many people do exactly as you wrote, but it doesn't seem worth the risk to me when it takes maybe 1-2 gallons of high pressure spray and 30 seconds to get the same result with no risk.

[themorb]

https://www.spectrawatermakers.com/u...le-upgrade-kit

Found this accessory although can't find any reviews or other information on it. I found a list price of ~$900 USD which seems about 5x what it should cost.

https://www.amazon.com/iSpring-Flush...42&sr=8-6&th=1

Looking at water filter kits for well water, etc. on Amazon it appears fairly common to have a drain on the bottom and a flush valve. Some coarse filters even have a mechanical scraper built in. Why not throw this in front of my 20 micron and flip the valve and flush it periodically?

[BlueH2Obound]

Mark, that's a good point! However, many people do not have access to high pressure spray while out cruising. Anyway, dragging has worked well for us, and we don't typically drag in "dirty" water, and have never had a problem to date. YMMV.

[BlueH2Obound]

themorb,

We went with a spa filter similar to this:

https://www.poolsupplyunlimited.com/...rm=%7Bquery%7D

The filter elements are readily available, and the spa filter has a filter area of 50 square feet, and works especially well in areas of high silt content.