TDS Water Quality Tester – TDS, EC & Temperature Meter 3 in 1, 0-9999 ppm Meter, LCD Display, TDS Meter for Drinking Water Test, Coffee, Swimming Pool, Aquarium, RO/DI Water, Hydroponics
TDS meters can are helpful for brewing if you’re using a RO filter or if you purchase RO (reverse osmosis) water for brewing. If you’re using an RO filter a TDS meter tells you how effective your filter is and can help you know if your filters need to be replaced. If you buy RO water, a TDS meter can let you know what you’re getting as some water processors add minerals back for flavor. A TDS meter will allow you to make sure you’re getting what you want.
RO water can be built up to reflect the exact water profile you’re looking for. See: Water by John Palmer and Colin Kaminski