Actually stevensuf is right, chlorine found in tap water can destroy a saltwater membrane. But it would take a lot more than four gallons even recylced. But absolutly use four or five gallons of distilled water. Remember to route
your pick up line, your brine discharge line, and your product tube into the same five gallon bucket.
Also this is very important! If your system is pickled (stored with a chemical agent) you will have to first flush out the storage
chemicals without applying pressure to the system. This can be done with your boats fresh water system routed through a new charcoal filter designed for watermakers. Your Sea Recovery
should already be plumbed this way. If you're not sure if your system has been pickled, treat it like it has been. You'll cause damage to the membrane by pressurizing the system while storage
solution is still present. This should be covered in your manual. If you don't have one or are unsure on what to do you can always ask me first.