For my system here are the directions from Dessalator.  They have been slightly edited from the original translated version for clarity, and adjusted for the model installed on my Amel:

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If the system will be out of service for more than one month:

1.  In a bucket, make a solution of 10 liters of water, 100 grams of Sodium bisulfate, and 2 liters of glycerine. Mix completely. [If I am not going to be in a cold water zone, I skip the glycerine]

2.  Place the suction hose from the pressure pump and the brine discharge line from the membrane in the bucket.

3.  Open the pressure regulating valve completely.

4.  Run the pump for 10 minutes circulating the solution through the seawater side of the membrane.

5.  Shut down the pump, and return hoses to their normal con nection points. Discard contents of the bucket.

For RE-START after storage:

1. Open pressure regulating valve completely. 

2.  Start the pump and run seawater through the system for 10 minutes with no back pressure.

3.  After 10 minutes of flushing, slowly rotate the pressure regulating valve clockwise until the flow gauge indicates the correct flow rate of product water, not exceeding 65 bar inlet pressure.

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Dessalator's current product instructions use a "sterilizing cartridge" that dissolves the sodium bisulfate in-line and a straight glycerine solution made in a bucket.  What we call glycerine in the USA is called "gylcerol" in Europe.  I will give odds that got confused with gylcol at some point by somebody with limited chemistry ba ckground.

Bill Kinney

SM #160 Harmonie

Annapolis, MD