Filters for watermaker

[Dane]

I am installing a DIY watermaker prior to a one year sail to the Caribien from Europe. I will have a 20 micron filter followed by a 5 micron filter before the high pressure pump.

How often must these filters be changed out? I don't want to bring to few or to many..

[Nauticatarcher]

We use pleated washable filters and have a pressure guage so we can see when they become blocked, we wash them carefully and then soak them in a 20% bleach solution using a plastic pasta storage container for a couple of days and then give them another fresh water wash and air dry , we get 4-5 uses of each filter

[Dane]

Thats sound environmentally friendly! For how long time can a filter operate before it must be cleaned?

[GordMay]

Water filtre longevity is dependent upon how contaminated the water supply is, whether you have a sea strainer ahead of the filtres, and watermaker run time.

In waters with a large amount of suspended particles (shallow bays), the pre-filtre will have to be cleaned or replaced more often, than when in clearer offshore waters.

Plastic, polyester, and other permanent element (reusable) water filtres, often 30 to 50 micron (300 mesh) , are generally only used for sediment pre-filtering ahead of a finer 5 micron disposable filtre.

I don’t generally recommend sanitizing watermaker pre-filtres with chlorine (which will destroy the membrane). Note that Nauticatarcher takes great care to rinse & dry his filtre element after washing.

Many manufacturers recommend a supply water booster pump be installed, when a 5 micron filtre is installed (or the high pressure watermaker pump is “close to” or above waterline)

[Dane]

I will have a sea strainer (to be specified..) and both a 20 micron filter and 5 micron filter. I will use a booster pump and have a pressure gauge tell me when it is time for filter change. I will be cruising only for a year and then the watermaker will see very limited use. Consequently I will go for disposable filters (5 and 20 microns).

I was looking for ball park figures based on what people experience. Are we talking 2-3 weeks or 2-3 months between changes for an average cruising behaviour..

[GordMay]

I'd say we're talking about 2-3 months between filtre changes.
Depending on where you are, replacement filtre cartridge elements should be readily available (they are a common commodity).

[funsailthekeys]

We use a power survivor 80 and when traveling change filters about once a month.

[Dane]

Thanks everybody!

[George Elliott]

If you put a low preasure switch on the system after the feed water pump you'll get notification when it's time to change because the switch won't allow negative preasures. The time to change varies with the brine water discharge rate, gpm. George

[Jim St.Pierre]

Hello everyone that has a water maker. I have one as well and a two questions. First off, I will be (hopefully) crusing next winter (09). I have a PUR 80 Survivor. I purchased the vessell last March and it was equipped with the water maker. It has not been used for 7 years, I think the membranes are still in the housing (2). I have two membranes that are still in the origanial packaging. Question # 1.... ARE THEY STILL GOOD???????? Secondly, Should I rebuild the pump befor starting up the system. It was checked out 1n 1999.. Thank You all for any help here.....Jim

[Badsanta]

Call PUR they have a DVD about rebuilding, looks simple. Mine is in the same shape as yours. I removed it to check it out, but have not done so yet. I am concerned about mine, I was told that it was pickled and have since found that pickling will not help with freezing. I am concerned about internal damage. I would think that the NEW membranes are probably OK the others may not be. Looks like an easy fix. Let me know what you find!
I did go to a water maker school. They all do the same thing just some better than others. Some things I found was that pickling is hard on the membrane and each use causes dome dammage and instead of pickling them, use a potable water system antifreeze The pink RV stuff, pump it through under NO pressure. That will preserve the membrane better, protect from freezing and is cheaper. But hard to find in the south. Do NOT use booze, vodka or anything like that as it will really mess with the
o-rings, Also the key is to use the water maker almost everyday, not all day but enough to flush the system. Otherwise you have to pickel after 7 days to keep the bugs out. That the more you use it the better. Thanks Al

[Jim St.Pierre]

Thanks Al, I called PUR and the lady there told me, the new filters I have are no good. This is very discourageing, as i thought they were and the replacement cost are very high for the membranes. I would like to know if the membranes I have (in new packaging) are still good.???? I understand that you need to use the system weekly there is no problem. I will be useing the system next winter all the time, as I hope to be in the carribean by then. I won't start up the system till then, but I do want to be ready with no surprises... Thank you again for your thoughts and coments..Jim

[Badsanta]

I would clean and run the unit with the old membranes to get things going. Take them out and take a look. Then I would try the new old membranes next, who knows, they may work. At least you have some time to ork it out. Keep us posted.

[Jim St.Pierre]

I have it out of the boat now. The boat is on the hard for the winter. I could put in operation next summer, but the water here is silty and somewhat dirty. The Membranes would not last long and to expensive to just be tring out....I think the pump system is okay, I will rebuild it befor I go , though. Thanks for your info... Jim

[Badsanta]

They test with clean water and salt at the shop, not dirty water. get a PPM -parts per million water tester about $60, you will need that anyway to test your water as you use it. It will tell you if the membranes work or are failing