The AutoAqua Digital Triple Inline TDS Titanium S3 is a compact, user-friendly digital inline TDS meter designed for saltwater aquarium hobbyists. It accurately measures the Total Dissolved Solids in your water, ensuring that the water produced by your reverse osmosis or reverse osmosis/deionization system is of suitable quality for your reef tank. This innovative device features three durable titanium probes, offering superior corrosion protection and allowing for comprehensive monitoring at various stages of your RO/DI system, such as source water, post-membrane, and post-DI cartridge. Its magnetically coupled controller allows for easy mounting, while a bright, easy-to-read screen and simple push-button operation provide quick and accurate TDS readings with an impressive +/- 2% accuracy. The Titanium S3 is an indispensable tool for anyone utilizing an RO or RO/DI system, providing precise insights into water quality. By monitoring your inlet and outlet water, you can effectively determine the optimal time to replace filtration cartridges, preventing the introduction of harmful dissolved solids into your aquarium and maintaining a pristine reef environment.