Just fixed my outdoor water filter today - DIY. Normal FRP935 with 5 layers filtration. For ordinary household usage you do not need all those expensive filters. For indoor I have a 1st stage pensonic filter followed by a national filter. The water is very clean and I sometimes drink without boiling. I make ice straight from the filter. I do not think all those expensive brands will make the water any cleaner than my present setup. To set your mind at peace just boil the filtered water. My outdoor filter cost RM399. DIY RM25.