TDS Meter with LCD Display. TDS meters measure Total Dissolved Solids in water.
TDS meters can are helpful for brewing if you’re using a RO filter or if you purchase RO (reverse osmosis) or DI water for brewing. If you’re using and 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 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 and DI water can be built up to reflect the exact water profile you’re looking for. See: Water by John Palmer and Colin Kaminski
Update: Since this post was published the price, availability or promotion has changed. Check the product page for current description, price and availability. Also: Today’s Deals on Amazon