As I mentioned in Lessons Learned we operated the watermaker for the first time this past November and were generally pleased with it's performance. It is rated at 25 GPH and during the first use, produced 20 GPH which I thought was acceptable considering the temperature of the water we're in, 83F.
When we returned to Subic I followed precedure to pickle the unit. On the next trip to Puerto Galera beginning on December 20th we used the watermaker again and to my dismay it only produced 13 GPH. When we returned to Subic on the 2nd of January I did the two step chemical cleaning process but it did little to improve on the 13 GPH. I contacted Village Marine and after I provided them with the serial number they informed me that the unit was pickled at the factory on August 21, 2006 before shipping to SHM. That factory pickling is only good for six months before the unit has to be commissioned, or put in operation.
VM said that the length of time between factory pickling and first use, 16 months, was most likely the cause of the membranes being clogged and the only solution is to replace the three membranes at $250.00 USD each. They did say because of the situation they would give me a break on the cost. The bottom line is that with shipping I will still have over $750.00 in the cost plus they will have to be installed.
I consider this to be an error on my part and probably one of the most expensive lessons learned next to the $1,500 Balmar upgrade. The reason I'm posting this here is to encourage you, any of you getting a watermaker, to research the operation manual and save yourself some headaches.
I asked VM why it produced 20 GPH the first time and only 13 GPH the second time. Their reply was that once the membranes start to foul, each use will be worse than the one before. They also stated that even in 83F water it should produce 25 GPH. Another good bit of information was not to pickle it unless we were leaving the boat as the harsh pickling chemicals also tend to clogg the membrane. The alternative solution was to do a backwater flush every other day when the unit is not being used regularly to make water.

Randal Johnson

Having earned a good living selling desalinators since 1986 I can add a few important observations....the prefilters on any "ripshitandbust" ( any unit using a three stage high pressure pump)type desalinator need to be BIG....elements with a minimum size of a loaf of bread not a litre of milk which is being fitted to most....look at HRO web site...and you need a couple on some large capacity units...one maybe an oil water sep...From the factory if a manufacturer uses the right initial biocide it is usually good for minimum 12/18 months...this mix is stronger than the maintinance biocide an owner uses and needs to be fully flushed on the first commisioning.

You need two types of membrane wash when cruising...one is an acid wash the other an alkaline wash....you can wash a membrane heaps of times but the less the better as each time you open up the pores of the membrane a little and therefore let a little bit more salt through, shortening the life of the membrane.

You have two types of fouling on the membrane...mould or slime ,same on the bottom of your hull...or scale from coral reef areas and other sources.

If a membrane ever dries out it will crack up like Mud Flats and let salt water through so you have to keep them moist all the time.

So called dud membranes can sometimes be revitalised with a supper strong hot water acid then alkiline wash a few times and let it soak in the wash....any petrolium products in the water can instantly kill a membrane ...even vasaline on the O ring of a prefilter...so na oil sep. is a good idea and I would never use a desalinator in a marina....also any clorine will instantly burn the membrane so do not put clorinated fresh water through the unit...ie from a town supply on the marina if it smells/tastes anything like clorine.

One of the problems with "modular" units is they never specify the prefilter systems or they give the basics ...if you look at the HRO web site check out all the types and size of prefilters??? get the big ones...if you buy the standard mounted units they come as standard with the BIG prefilters.

Personally I perfer the 12/24 volt units for Duck size boat....easy to manage...I sold Thousands of Katadyn Survivors to Aust military and boating people...simple/ reliable and always prefere to be run regularly rather than left sitting....I have the 160 model on ICE with an oil water sep, and two prefilters ( litre size)3 in total which is just big enough for us...about 60 gall an hour raw water flow.

In the early days Spectra had major issues but now they too are very good units...just go with the simple models and forget the bells and whistles.

The "ripshitandbust' pumps are a nightmare to maintain and can be easily damaged where as the 12/24 volt units are easy to do all the maintinance onboard yourself with no previouse experience and the Katydan models are the best in the world for this...you can carry everything to do it all no matter what the problem......way to go,,...

If you want to help your water maker...fit at least one manual salt toilet, a salt water deck wash and a salt water foot pump in the galley....

1. Why does the manufacturer pickle it in the first place.
Answer: I don't know. They reported to me that the membranes and vessels are tested after assembly so maybe they have to be pickled after that. Several years ago I spoke with Bill Lee whom SHM use to buy their watermakers from before he retired. I asked him considering our cruising plans shouldn't we carry an extra set on Membranes. He said no, the new membranes have a very short shelf life. Maybe this is why they pickle them too.
2. What does Village Marine recommend for pickling.
Answer: I used sodium metabisulphide and I think that is the preservative in their pre-loaded pickling filter. They said they developed the chemically loaded filters because there was such a problem shipping the powered chemicals.
3. If the boat is left for 6 months what is one to do. Can the NF-600 auto flush every other day
Answer: Apparently this has to be addressed within the period specified or you will be in the same picklement I am.

4. What else causes the membranes to become clogged, and is this a function of a clogged primary filter.
Do you have a oil filter in addition to a sediment filter?
Answer: I have a small filter screen, an oil/air separator, and a five micron prefilter inline before the seawater gets to the high pressure pump. My understanding is that stagnant water is the fouling problem. The five micron filter housing is clear so it is very evident when it starts to turn black.
My unit is the No Frills 600 GPD unit, the more expensive ones may be more automation. I'm sure it's possible to put an electric valve on the fresh water pressure line going to the backflush filter with an electronic control, this could be programed to run whenever for however long you chose.
The bottom line is this: Watermakers need lots of attention. It is not that time consuming once they're understood but there is alot of energy expended understanding them, at least for my brain.
Randal Johnson

Randal

A couple of questions
1. Why does the manufacturer pickle it in the first place if it is only good for 6 months, after which damage will ocurr. Does it have a best before date on the box

2. What does Village Marine recommend for pickling. We discussed that I think it is sodium metabisulphide. Will the manufacturer come clean on exactly what their kit contains

3. If the boat is left for 6 months what is one to do. Can the NF-600 auto flush every other day

4. What else causes the membranes to become clogged, and is this a function of a clogged primary filter.
Do you have a oil filter in addition to a sediment filter