Re: Water maker Questions


Might "not taste anything," but most people cannot tolerate their drinking water with anything over 500ppm. Most people will retain water at 500ppm. Before you start abusing your body to save a few euros on membrane costs, you might want to ask your doctor.

Tom, I can't answer your question about "acceptable" in your situation because I don't believe you gave specifics in ocean water. Watermaker output depends on many things, including pressure, membranes, pressure maintained, salt content of the water, and even temperature. Your D60 new membranes should produce 1 liter a minute +/-10% when making freshwater from ocean water and a pressure of 50 BAR on the outside of the membranes. If your membranes are 2 years old, the TDS should be around 250 after about 5 minutes of production. In 1 hour the TDS may improve slightly.

It is true that Dessalator has waffled on what is good quality in terms of TDS. The WHO states 500ppm or less. Spectra Watermakers say 1000ppm, or less (a laugh everytime I hear this). Judy and I changed membranes about every 4 years because we could definitely tell when the TDS moved above 325-350.

I hope this helps.


CW Bill Rouse
720 Winnie St
Galveston Island, TX 77550
+1(832) 380-4970

On Tue, Jul 23, 2019 at 2:01 PM Matt Salatino via Groups.Io <> wrote:
You won’t taste anything in your water below 1000 ppm tds.


On Jul 23, 2019, at 2:51 PM, Danny and Yvonne SIMMS <simms@...> wrote:

Hi Tom,
500 ppm is considered the upper limit, anything below that is acceptable for drinking water. However once the membranes get to the point of delivering either 500ppm of close to it they are arriving at replacement time. 280 is acceptable and of course at start up you will see higher levels. My duo 60 has manual controls and I run product water to waste for a couple of minutes after start up. So long as the tds goes down to an acceptable quite quickly dilution would deal with it. 0.75l/m is not far off 60 l/h the and if you give the watermaker some long use you may find you get it up there. So in summary. 500ppm is the upper limit but you wont die if it is a little higher. Anything in the mid 300 and below is quite acceptable. Once my tds gets over 400ppm on a regular basis I start planning for replacement. Like anything, the best treatment is regular use.
SM 299
Ocean Pearl
On 24 July 2019 at 05:05 Thomas Peacock <peacock8491@...> wrote:

I’m hoping to get a few tips on our water maker. We have a LaRochelle installed Dessalator, I believe a D60, SM 240, 24 volts only. We have used it only sporadically.
I put new membranes in 2 years ago. I am trying to be sure it works properly, we are in the Chesapeake Bay, which is only brackish water so we don’t use it there. Going to Martinique this fall.
The Dessalator manual at one point says we should have 250 TDS, at another it says 500, which certainly tastes brackish.
At 40 bar we get 270, at 60 bar about 330, which then goes down to 280 after about 5 minutes. We get 0.75 liters/minute.
Is this acceptable performance? I am more concerned about the TDS than the rate. I would like to clean the membranes as suggested by Dessalator, all they say is “cleaning solution”. Is this the same as the pickling compound, sodium metabisulfite?
Thanks as always for everyone’s insights.
Tom Peacock
SM 240 Aletes
Chesapeake Bay

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