... filter:8-10kg2)Active carbon filter:3.5kg3)Fist stage PP filter(1u):1pcs, filter price: USD2.50/ ... should be changed at least every three months4)Second stage pp filter(5u),1pcs, Filter price: USD2.50/ ... to avoid rust 12)Coin, card or paper money system, can design as per the currency from the ... machine firstly,the Ro system will be back wash around 4-5 minutes and the same time,the RO flush light will ...