Watermaker Schenker ZEN 100

Has anyone experience with the SCHENKER ZEN 100 watermaker?

For our in-build H508 #88 I think about to install this typ.

Sailing in the MED with 450 l main tank + 180 l additional tank

is maybe not enough for 3 cabins, showers etc.

Thanks for your informations - fair winds,

Christian

I have added one 100L tank to the 750 main tank, and it allows me to evaluate the water quality before filling the produced water into the main..

1) flushing. This is easy, but it's done every time the watermaker is operated so it needs to be automatic. You feed your pump with drinkable water, from your main tank, and the  brine circuit is now cleaned from the salt. Beware :if the main tank contains chlorinated water from the last filling from the water network of your last harbor, it is not good for the watermaker membrane, your most precious asset... 

2) cleaning. This is done less often, every time you don't use your watermaker for a while (monthly ? Once in a year? It depends on your use. If you use it every day, it could be never...if you stop using it for few weeks, it may be required). In this case, you take the brine outlet, and instead of going into the sea you put it back to the source. The source is a bucket, containing specific chemicals (two types depending on the problem you encounter, provided by schenker) that replaces the seawater at the entrance of the pump and once it reaches the membrane it cleans, sterilizes and purifies the membrane. It all goes into the brine circuit, and you need a close loop to run for few hours by filling the overall circuit (20L bucket?it depends on the volume of your tubing too).

... Now i am sure it's clear to you that a watermaker is the pool of the sailor: for little pleasure, a lot of work and hassles! 🤣 🤣 🤣

Specifically, you realize that if you have the brine exit very far from the seawater inlet, the second circuit is a long one! Additionally, I had to do it myself because the Shenker installation manual doesn't specifically describe it, simply saying you have to do it for the cleaning.... 

I am still learning, I have to start doing it myself.... In few weeks. I will tell you how it goes... And very curious to know from the other guys how it works in practice... 

Watermakers are often troublesome if not installed according the manufacturers instructions. You need the right salt water flow rate and pressures within the system. If you don't you will have continually have problems with water quality and/or output volume. If you are fitting a 12V or 24V system you need to make sure you are the right voltage at the motor/s when the system is running. Under voltage with cause the system to underperform.

Just a few comments - The manufacturers general suggest 3 products to use in the system - 1. Preservative or sometimes called a Biocide or referred to as pickling - this is normally a Sodium Metabisulphite but sometimes sold as "Solution #1".Product number 2 is normally a alkali with  product number 3 being a acid. 

The preservative is used if you are not running the system for a number of months up to a year. For storage over 1 year you need to change the preservative. The newer method of maintaining the system when not being used is manual or auto fresh water flush. The auto version of the FWF runs every 5-7 days (depending on the manufacturer) and flushes for 3-10 minutes (normally programable). If you are running your watermaker every day or every few days there it is not necessary to FWF the system. As Pzucchel mentioned chlorine in the flushing water will damage your membrane/s. You should make sure you fit a activated charcoal filter between the boats water tank/s and the waternmaker FWF system so any chlorine it taken out of the flushing water before getting to the watermaker membrane. If you are leaving your boat for a period you would need to make sure there is enough fresh water in your tanks for the FWF which may happen each week or so.

The alkali and acid cleaners are used once your notice a drop in either output (litres per hour) or higher than normal TDS (Total Dissolved Solids) or both problems. These cleaners do damage to membranes slightly so cleaning would probably be each 12 months or so or a longer interval if possible. Follow the manufacturers instruction for the alkali and acid cleaning. Some manufacturers call these products cleaner 2 and 3 and should be used alkali first, then flush out the system with FW and then the acid cleaner then flush again before using. If this cleaning does not return the output or TDS back to around normal then your membrane may need replacing. Membranes last about 5 years almost regardless of amount of use. Output and TDS are effected by seawater temp and salinity. Changes in output and TDS can often be caused by variations in these.

Most systems have 2 prefilters (20 and 5 micron) and these need to be cleaned or replaced regularly depending on the quality of seawater being put through them. Likewise there is normally a seachest basket or stainless steel plankton filter fitted before the pump/s and this needs to be cleaned regularly.

Fortunately watermaker technology has come a long way in the last 10-15 years and now if the installation is correct in the first place you should have many hours of trouble free operation. With two of us onboard we would normally make about 25,000 of fresh water a year and over 7 years our watermaker have given us very few problems.