okay if you have a solenoid valve this means that you have a booster pump. this solenoid valve has to be hooked up inbetween the membrane and filters because there is a lot of water pressure if you hook it up before the filters. if you do not have a booster pump then you would need a auto shut off valve. if you dont want to deal with this do what gumbii said... add a valve and turn if off when you are done.