Which brand of front water purifier is good

Choose a big brand, like the United States 3M these big brands of pre-filtration do better, the standards are higher, with more assured, but at the same time the price will be relatively high quite a lot. However, the right place can still get a lot of discounts! Like here in Beijing there is a group purchase will be called easy to install, that inside the 3M water purification will be cheaper than the price of the activities in the store several hundred, but also in the store to enjoy the after-sales service and service, quite affordable, water purification, this is something that only used to know how much the quality of life will be improved.