Are you tired of big, boxy, hard-to-read TDS meters? So are we! That’s why we built the AutoAqua Titanium Series TDS meters. They are small, easy-to-use, and have a big bright screen to make checking your TDS fast and easy. The Titanium S3 also has a magnetically coupled controller to make it easy to pick up and stick back on the metal frame of your reverse osmosis system. There is no other TDS meter on the market like it! The Titanium S3 features three titanium probes, which provides excellent protection against corrosion, to measure the Total Dissolved Solids (TDS) in your water. You can put one probe after your source water, another after your TFC membrane, and the third after the DI catridge. With a single push of a button, you’ll get an accurate reading of the TDS in your water! Push the button a second time to check TDS using the second probe. Push it again to check with the third probe. It’s so easy! The reason hobbyists measure TDS is to ensure the water produced by their reverse osmosis (RO) or reverse osmosis/deionization (RO/DI) system is safe to use in an aquarium. The Titanium S3 TDS monitor can be used to check the quality of your inlet and outlet water to help you determine when it’s time to replace the cartridges in your reverse osmosis system. This is the most common application for a TDS meter in our hobby and the Titanium S3 is ideal for the job with an accuracy of +/- 2%. You’ll know precisely when to replace your carbon block, DI resin, or TFC membrane to ensure your aquarium water is pure and so you aren’t throwing away good cartridges prematurely. It’s super easy to install, too. A ¼” push connect union tee is included to make setup a breeze. You can calibrate the Titanium One to ensure long-lasting accuracy. To conserve battery life, the unit will turn off automatically after 3 minutes of non-use. The battery is not proprietary, either.