Delhi tap water is not normal water.
The TDS (Total Dissolved Solids) level in Delhi’s municipal supply regularly sits between 400 to 600 mg/L — sometimes higher in areas like Dwarka, Uttam Nagar, and Rohini. The Bureau of Indian Standards recommends drinking water should be below 500 TDS, ideally between 50 to 150 TDS.
Your RO purifier is working overtime every single day to bring that number down to safe levels. And that constant heavy workload wears out your filters faster than most people realise.