Hi may i know 3M water filter need to change yearly or up to capacity reached? My situation is that I only have 2 person in the house, so not much water consumption. I saw from website that 3M AP902 can filter up to 100,000 gallon which is 273 gallon per day, which is possibly can last me few years. So need advise on this. Plus i am from Kuching, sarawak. Hardly and not much choice for water filter brand. I got a quotation that 3M AP902 include installation is RM1600+