Watermaker care
This is based on eleven years of experience with watermakers from the size of a Pur (35 gallons per day) to the 40,000 gallon per day system here at the marina that I manage. Reverse osmosis watermakers (there are other kinds) are basically very simple machines, but they need maintenance, and lots of it. Let's face it, the combination of salt water and 800 pounds of hydraulic pressure is enough to put wear on any system, no matter the size. Membranes do like to be used regularly. Apart from maintenance, we NEVER shut down our system at the marina, preferring to discard excess water. We get about four years of use out of each membrane. We have twelve, and we swap out three every year. This is based on quite a period of experience and observation. As the membranes age, they pass through more and more parts per million, until the quality of the water no longer measures up to the desired standard. Ideally, all membranes would be run continuously, but it is unrealistic on a boat. Membrane manufacturers state that a membrane will age equally when used intermittently or constantly, and four years is not a bad figure. It makes no sense to carry a spare, as it will age in its packaging, or even dry out, in which case it will become unusable much more quickly. So you use one until it starts to go bad, then you buy a new one. The distributors don't like to keep them around for long, either, by the way! Back to a boat. Use will be intermittent. It is best to use the membrane frequently, so a short period every day, or every other day, is a better practice than running it for several hours every week or so. It does help to flush it with product water after use, and flushing it can take the place of using it, at least for awhile. If you are going to let it sit for a considerable period, then you need to use a biocide. Use the one specified by the manufacturer, as they can affect other parts of the watermaker adversely. Watermaker manufacturers will state that their recommended biocide will not hurt their units (Spectra had a fairly disastrous time of it when their biocide manufacturer supplied them with a bad batch....Spectra users are well acquainted with this unfortunate occurrence), but my experience is that watermakers seem to be more likely to need a servicing immediately after being put back into service after a "pickling" than at any other time. Take that for what it is worth. Bottom line is that you should use your watermaker as regularly as possible. You need to become comfortable with servicing or even rebuilding it, because you will have to. Flush it with fresh water after use. Biocide if you are not going to use it for a period of weeks or months, less in hot humid weather. Plan on a new membrane every four or five years, regardless. Never run it in oily water or flush it with chlorinated water. And finally, you might want to do what I do with the one on my boat, which is to put it back into service after pickling, by going out and using it the day BEFORE a cruise or voyage. That way, if it needs maintenance, I can still do it at the dock or at anchor. Good luck. Hope this helps.
