Re: Excessive usage of water maker membranes

Paul Dowd and Sharon Brown



I was told by Martin to run the water maker with the pressure at the beginning of the green zone. It also says this in the manual.




S/Y Ya Fohi - Amel 54 #98 - Grenada


From: <> On Behalf Of Mohammad Shirloo
Sent: 19 April 2020 08:32
Subject: Re: [AmelYachtOwners] Excessive usage of water maker membranes




When we first purchased Kokomo, I had detailed discussions with Martin, the head tech at Dessalator, about the environments that the water maker could be used and best practices. The following was my takeaway:


  1. The water maker can be run safely in most waters. This includes harbors, marinas and even water that is not clear. I was told that the main detriment would be more frequent changes to the pre-filters.
  2. The water maker can be, and should be, run in the high end of the green zone. This will lead to more water production, without any downsides.
  3. Performing an auto fresh water flush after every usage is unnecessary and wastes about 20 liters of fresh water. As long as the water maker in run at least every week, a fresh water flush is unnecessary. We simply stop making water by shutting down the switch and then backing out the pressure valve.
  4. Utilize the powder provided by Dessalator to prep the membranes for the winter season.


We have done the above for 5 seasons of about 5 months each. The pre-filters typically last a whole season. We never put any water in the tank other than from the water maker. The water quality is always below 250 PPM. When we purchased Kokomo, the water maker had only 60 hours on it. So, I’m fairly sure that our membranes are original from 2008 and therefore 12 years old. The water maker now has around 550 hours. I was told that after 500 hours, the quality will probably start to drop. Our usage has solely been in the Med.


Happy Sailing;



Mohammad and Aty

B&B Kokomo

AMEL 54 #099


From: <> On Behalf Of Mark Erdos via
Sent: Saturday, April 18, 2020 9:35 PM
Subject: Re: [AmelYachtOwners] Excessive usage of water maker membranes


Hi Colin,


Yes, I re-read that part and it is a little confusing how I wrote it. In marina, we do a fresh water flush aobut once a week. We do not run the water maker in that environment.


Thanks for the insight, I guess I need to be more fussy about where we run it. I thought the pre-filter would help a lot. I guess not.



With best regards,





Sailing Vessel - Cream Puff


From: [] On Behalf Of islandpearl2_sm2k332
Sent: Saturday, April 18, 2020 10:47 PM
Subject: Re: [AmelYachtOwners] Excessive usage of water maker membranes


Hi Mark


We had the 100L/Hr Duo on Island Pearl II and went around the work in three years with a new 2016 set of membranes. Those membranes were still perfect at the end of our trip doing a full 100L/Hr easily on the a/c current but slightly down to 75L/hr on the DC current motor. 


We were absolutely fussy about the cleanliness of ocean water before running it and were sometimes scoffed at by others eg in Rodrigues (Indian Ocean) for lifting anchor, risking losing our good spot to go out to sea every four-five days to make water whilst other cruiser friends simply made water inside the large seawater harbour where we felt the water was not up to scratch. Also, we never took the boat out onto the hard for a season, even though we had planned to do this in the Caribbean in 2019.


If you are careful like this, which I suspect you are, then there must be something else at play with your system and I look forward to hearing about that from other more experienced cruisers here.


Also, since we have communicated often and I admire your equally careful approach to looking after Creampuff, I highly suspect that when you refer to "running your watermaker at least once per week in marina's", that you actually meant "doing a freshwater flush cycle" in the marina from your tank as per the manual requirements.... rather than actually making water from the extremely dirty marina seawater which would totally explain everything about your problems, but which I am equally sure you would never have done. 


Colin Streeter

Brisbane ex Island Pearl II


On Sun, Apr 19, 2020 at 12:10 PM Danny and Yvonne SIMMS <simms@...> wrote:

Hi Mark.

I am very careful about where i run my watermaker. Never in a marina and it has to be an exeptionaly clean harbour before I will run it there. Also I am paranoid about even traces of chlorine. It is many years since I allowed any chlorinated water into my tank. However you living full time aboard would suggest a lot of use. Like a car,  its not the time that wears them out but the milage. 



SM 299

Ocean Pearl

On 19 April 2020 at 12:21 Mark Erdos <mcerdos@...> wrote:

I need a little help with water maker usage and maintenance, please.


Cream Puff has a 24v D60 water-maker. My problem is we seem to be going through membranes at the rate of a pair a year. I have read where others have used the same set of membranes for years and still get drinkable water. This is not the case with us. We are in our 5th year of full time cruising and are now on our 6th set of membranes.


When I last change membranes in Colombia, this was about March 2019. Our current membranes are just over a year old. The PPMs are starting to creep up a bit now and we have gone from the 300 range to the 500 range. We notice a change in drinking quality over 600 PPMs. This is when we usually change the membranes.


We run the water-maker at least once a week when in a marina, flush it with the fresh water rinse. I have a double charcoal filter set up for the tank rinse. When on anchor it is run just about every day. I am careful to watch the pressure and water making float gauge. I normally set it at 55 liters per hour and this put the pressure in lower side of the green range.


Any ideas why our membranes are not lasting or why our PPMs creep up?



With best regards,





Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Tahiti, French Polynesia






Colin Streeter

0411 016 445

Ya Fohi - Amel 54 #98

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