I was just wondering how often you all change the water in your spa? I heard every 6 months and then some say once a year. We have a stand alone spa on a deck and we don't use it everyday. I would say once or twice a week in the summer and maybe 2 or 3 times a week in the winter. We have a 400 gallon spa and the water is very clear and sparkly! 
Just wondering if there is any 'set' answer on this? Thanks!
Just wondering if there is any 'set' answer on this? Thanks!