Use deionized water. It is very pure with all of the impurities removed and it takes more of the flavor out of the coffee grounds so your coffee is stronger and more flavor.

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Roy D. Browning \r\nCoastal Instruments (Dandong) Co., Ltd.\r\nNo.7 Industrial Compound, \r\nTongxing Zhen'an District, \r\nDandong, Liaoning, P.R. China 118011 \r\nPhone: 086+415-613-2608 Fax: 086+415-613-2798 \r\nChina Mobile: 086+130-5033-6757