Water purifiers equipped with TDS (Total Dissolved Solids) controllers are modern marvels, offering advanced filtration technology to enhance the quality of our drinking water. While we cannot say which of these can a water purifier not do, there are advanced purifiers such as RO and UV ones that can help definitely reduce TDS levels. 

Maintaining Mineral Balance

While water purifiers with TDS controllers aim to regulate the TDS levels in water by maintaining a balance between essential minerals and contaminants, they can't differentiate between harmful and beneficial dissolved solids. In some cases, they might remove crucial minerals alongside impurities, affecting the water's overall nutritional value.

Addressing Microbial Contamination

Water purifiers, including those with TDS controllers, are efficient at removing dissolved impurities and certain microbes. However, they might not eliminate all types of bacteria, viruses, or cysts, requiring additional UV or other disinfection systems to ensure complete microbial safety.

Neutralizing pH Levels

TDS controllers primarily regulate the quantity of dissolved solids but may not actively alter the pH levels of water. Ensuring an optimal pH for health benefits might require separate pH-enhancing mechanisms or additional filtration stages.

Handling Chemical Contaminants

Certain chemicals and pesticides might not be entirely removed by conventional water purifiers, including those with TDS controllers. Advanced purifiers with specific filters designed for chemical removal might be necessary for complete elimination.

Eliminating Radioactive Elements

Radioactive contaminants in water, such as radium or uranium, pose a significant health risk. While TDS controllers help manage dissolved solids, they might not entirely eliminate radioactive elements, necessitating specialized filtration methods.

Overcoming High TDS Challenges

In areas with extremely high TDS levels, water purifiers, even those with TDS controllers, might struggle to reduce TDS to recommended levels. In such cases, additional purification methods like Reverse Osmosis (RO) might be required.

Water purifiers with TDS controllers are undoubtedly valuable assets, ensuring safer and cleaner drinking water by managing TDS levels. However, understanding their limitations helps in making informed choices and implementing supplementary measures to address specific water quality concerns.

For comprehensive water purification, combining TDS control with supplementary purification technologies tailored to specific contaminants and local water quality challenges ensures the most effective filtration and safety for your drinking water. Always consider regular maintenance and periodic water quality checks to ensure your purifier operates optimally.