{"id":7317,"date":"2026-10-24T01:17:37","date_gmt":"2026-10-23T19:47:37","guid":{"rendered":"https:\/\/www.rentomojo.com\/blog\/?p=7317"},"modified":"2026-10-24T01:17:37","modified_gmt":"2026-10-23T19:47:37","slug":"best-water-filters-for-home-delhi","status":"publish","type":"post","link":"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/","title":{"rendered":"How to Choose the Pre-Filters for a Water Purifier in Delhi"},"content":{"rendered":"<p><span style=\"font-weight: 400;\">The tanker and borewell water in Delhi often carries sand, silt, and other physical sediments. Due to the high levels of sedimentation, your water purifier\u2019s filters work overtime. Or the pre-filters can choke very quickly. Now, if you have a water purifier without the necessary pre-filters, your water might not be safe to drink.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The first sign you might notice is that your RO needs frequent filter changes. Pre-filters are basically the low-cost cartridges through which the water passes before it goes to the RO membrane. Their main job is to trap sand or rust before they reach the water purifier\u2019s filters. This is why you should know how to find the pre-filters for a water purifier in Delhi.\u00a0<\/span><\/p>\n<p><strong>Also Read: <a href=\"https:\/\/www.rentomojo.com\/blog\/water-tds-level-in-delhi\/\">Water TDS Level in Delhi: Safe Limits and the Right Purifier<\/a><\/strong><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_68_1 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title \" >Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #302d55;color:#302d55\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #302d55;color:#302d55\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#What_is_a_Pre-Filter_in_RO_What_Does_It_Do\" title=\"What is a Pre-Filter in RO? What Does It Do?\u00a0\">What is a Pre-Filter in RO? What Does It Do?\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#What_are_the_Best_Pre-Filters_for_Home\" title=\"What are the Best Pre-Filters for Home?\u00a0\">What are the Best Pre-Filters for Home?\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#Types_of_Water_Filters_for_Indian_Homes\" title=\"Types of Water Filters for Indian Homes\u00a0\">Types of Water Filters for Indian Homes\u00a0<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#1_Carbon_Filter\" title=\"1. Carbon Filter\u00a0\">1. Carbon Filter\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#2_Iron_Filter\" title=\"2. Iron Filter\u00a0\">2. Iron Filter\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#3_UV_and_UF_Filters\" title=\"3. UV and UF Filters\u00a0\">3. UV and UF Filters\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#4_RO_Membrane\" title=\"4. RO Membrane\u00a0\">4. RO Membrane\u00a0<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#How_to_Choose_the_Best_Water_Filter_for_Your_Home_in_Delhi\" title=\"How to Choose the Best Water Filter for Your Home in Delhi?\u00a0\u00a0\">How to Choose the Best Water Filter for Your Home in Delhi?\u00a0\u00a0<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#Use_a_Glass_Test_to_Find_a_Water_Filter\" title=\"Use a Glass Test to Find a Water Filter\">Use a Glass Test to Find a Water Filter<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#Does_Borewell_Water_Need_a_Pre-Filter_for_Purifiers\" title=\"Does Borewell Water Need a Pre-Filter for Purifiers?\u00a0\">Does Borewell Water Need a Pre-Filter for Purifiers?\u00a0<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#How_to_Choose_a_Pre-Filter_for_RO\" title=\"How to Choose a Pre-Filter for RO?\u00a0\">How to Choose a Pre-Filter for RO?\u00a0<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#1_Decide_on_the_RO_Pre-Filter_Cartridge\" title=\"1. Decide on the RO Pre-Filter Cartridge\u00a0\">1. Decide on the RO Pre-Filter Cartridge\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#2_What_is_%E2%80%9C5-Micron%E2%80%9D_on_an_RO_Pre-Filter_Cartridge\" title=\"2. What is \u201c5-Micron\u201d on an RO Pre-Filter Cartridge?\u00a0\">2. What is \u201c5-Micron\u201d on an RO Pre-Filter Cartridge?\u00a0<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#How_Often_Should_You_Change_an_RO_Pre-Filter\" title=\"How Often Should You Change an RO Pre-Filter?\u00a0\">How Often Should You Change an RO Pre-Filter?\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#Conclusion\" title=\"Conclusion\u00a0\">Conclusion\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#Frequently_Asked_Questions\" title=\"Frequently Asked Questions\u00a0\">Frequently Asked Questions\u00a0<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#1_Which_water_filter_is_best_for_home_and_health\" title=\"1. Which water filter is best for home and health?\u00a0\">1. Which water filter is best for home and health?\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#2_Can_we_use_RO_without_a_filter\" title=\"2. Can we use RO without a filter?\u00a0\">2. Can we use RO without a filter?\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#3_Can_a_pre-filter_reduce_TDS\" title=\"3. Can a pre-filter reduce TDS?\u00a0\">3. Can a pre-filter reduce TDS?\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"#\" data-href=\"https:\/\/www.rentomojo.com\/blog\/best-water-filters-for-home-delhi\/#4_When_should_the_pre-filter_be_replaced\" title=\"4. When should the pre-filter be replaced?\u00a0\">4. When should the pre-filter be replaced?\u00a0<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"What_is_a_Pre-Filter_in_RO_What_Does_It_Do\"><\/span><b>What is a Pre-Filter in RO? What Does It Do?\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Think of the pre-filter as a sieve. It can hold back sand and flakes of pipe rust while water and sediments flow through. The pre-filters are the most delicate part of your water purifier. When the pre-filters do not work properly, anything solid landing on the RO membrane stays there. This slows down the flow until the membrane wears out.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Most water purifiers have a small sediment stage inside the unit. The external RO pre-filter goes a step earlier, on the pipe that feeds the water purifier. It can take out heavy dirt first, before any of it reaches the cartridge.\u00a0<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_are_the_Best_Pre-Filters_for_Home\"><\/span><b>What are the Best Pre-Filters for Home?\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400;\">The best water filters for home depend on your water supply. Each filter has its own job.\u00a0<\/span><\/p>\n<table>\n<tbody>\n<tr>\n<td><b>Filter<\/b><\/td>\n<td><b>What it removes<\/b><\/td>\n<td><b>What it can&#8217;t do<\/b><\/td>\n<td><b>Who needs it in Delhi<\/b><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Sediment pre-filter<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Sand, silt, rust flakes<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Remove salts, germs, or smells<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Borewell and tanker homes<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Activated carbon<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Chlorine, odd smells and tastes<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Lower TDS or kill germs<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Almost every home<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Iron removal filter<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Dissolved iron<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Lower TDS<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Borewells that leave orange stains<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">RO membrane<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Dissolved salts (TDS) and hardness<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Survive heavy sediment<\/span><\/td>\n<td><span style=\"font-weight: 400;\">High-TDS borewell or mixed supply<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">UV \/ UF<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Bacteria and cysts<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Lower TDS<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Low-TDS piped water, or as a final stage after RO<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>Also Read: <\/strong><a href=\"https:\/\/www.rentomojo.com\/blog\/calculate-tds-for-water-at-home\/\">How To Calculate TDS for Drinking Water At Home<\/a><\/p>\n<h2><span class=\"ez-toc-section\" id=\"Types_of_Water_Filters_for_Indian_Homes\"><\/span><b>Types of Water Filters for Indian Homes\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400;\">To handle sediment, you need a sediment pre-filter. It is generally a spun polypropylene cartridge rated at 5 microns.\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"1_Carbon_Filter\"><\/span><b>1. Carbon Filter\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The carbon pre-filters can help fix the taste and smell of the water. DJB water is chlorinated, and a carbon pre-filter can get rid of metallic or musty notes. It protects the RO membrane, which chlorine slowly damages. So, RO water purifiers have a carbon stage in front of the membrane. Some people add the carbon stage after to improve the taste.\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"2_Iron_Filter\"><\/span><b>2. Iron Filter\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400;\">If you see orange stains in the buckets, the water might carry excess iron. Borewell water is likely to have dissolved iron that looks fine at first. However, once you leave it in the tank, it reacts with air and turns into reddish-brown specks. A sediment cartridge catches it after that happens. You need a dedicated iron filter before the purification process.\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"3_UV_and_UF_Filters\"><\/span><b>3. UV and UF Filters\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400;\">UV lamp can kill bacteria and viruses. UF membrane can physically block bacteria and cysts. None of it touches the dissolved solids. If it is low-TDS piped water, UV and UF can work well. High TDS in water calls for an RO.\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"4_RO_Membrane\"><\/span><b>4. RO Membrane\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400;\">RO membranes work well enough for dissolved salts. It is also the stage that sediment can affect. The pores of an RO membrane are finer than anything else in the water purifier. It usually sits behind a series of cheap filters that take the first hit.\u00a0<\/span><\/p>\n<p><strong>Also Read: <a href=\"https:\/\/www.rentomojo.com\/blog\/buying-vs-ro-on-rent-delhi\/\">Buying an RO vs RO on Rent in Delhi: AMC, Filter Changes<\/a><\/strong><\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_to_Choose_the_Best_Water_Filter_for_Your_Home_in_Delhi\"><\/span><b>How to Choose the Best Water Filter for Your Home in Delhi?\u00a0\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400;\">The answer depends on your water source. But do you need a filter for DJB supply when the water seems clear and normal? A carbon filter with UV and UF is enough. Groundwater needs a sediment pre-filter and RO, along with an iron filter if you notice orange stains on the taps and buckets. Many households can get tanker water or a mix of different water sources in an overhead tank \u2013 such households need a sediment pre-filter.\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Use_a_Glass_Test_to_Find_a_Water_Filter\"><\/span><b>Use a Glass Test to Find a Water Filter<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Fill a glass with tap water that your water purifier purifies and leave it for an hour. If you find fine dust on the bottom, it means a 5-micron cartridge will work. If there is a layer of sand or mud, the purifier needs two stages. The yellow or orange tint shows that there\u2019s iron in the water.\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Does_Borewell_Water_Need_a_Pre-Filter_for_Purifiers\"><\/span><b>Does Borewell Water Need a Pre-Filter for Purifiers?\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Borewell water does not go through a treatment plant, like the DJB supply. If the bore is old or the water table has declined, the borewell water can carry sand. After delivery, you should wait a few hours before drawing water from the purifier.\u00a0<\/span><\/p>\n<p><strong>Also Read: <a href=\"https:\/\/www.rentomojo.com\/blog\/drink-hard-water-in-delhi\/\">Can You Drink Hard Water in Delhi? Find Out What Happens<\/a><\/strong><\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_to_Choose_a_Pre-Filter_for_RO\"><\/span><b>How to Choose a Pre-Filter for RO?\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Most people go to buy candles and choose whatever is available on the shelf. Since they do not know what pre-filter is being used and why, the RO is likely to choke overnight.\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"1_Decide_on_the_RO_Pre-Filter_Cartridge\"><\/span><b>1. Decide on the RO Pre-Filter Cartridge\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400;\">An RO purifier uses a spun filter by default. Its polypropylene fibres are incorporated into a thick sleeve, so dirt remains trapped through its full depth. It works for fine silt and is difficult to clean. Once the pre-filter turns brown, you need to discard it.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">String-wound cartridges with polypropylene yarn wrapped around a core can hold more sand and rust before they get clogged. They are suitable for old borewells.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Pleated cartridges can be washed. You need to rinse the sand off and refit them. They are sold in coarser ratings and allow fine silt through.\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"2_What_is_%E2%80%9C5-Micron%E2%80%9D_on_an_RO_Pre-Filter_Cartridge\"><\/span><b>2. What is \u201c5-Micron\u201d on an RO Pre-Filter Cartridge?\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400;\">A home cartridge has a nominal rating, which means it can catch most particles of that size. Two cartridges labelled 5-micron can work differently. You can run a test to understand. Between two cartridges of the same size, the heavier one has more filter material packed in.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">A finer micron pre-filter is not always better. If you get tanker water with mixed quality, a 1-micron cartridge chokes fast and blocks the purifier.\u00a0<\/span><\/p>\n<p><strong>Also Read: <a href=\"https:\/\/www.rentomojo.com\/blog\/how-to-choose-the-best-water-purifier-for-home-in-delhi\/\">Best Water Purifier for Home in Delhi (2026): A Complete Guide<\/a><\/strong><\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_Often_Should_You_Change_an_RO_Pre-Filter\"><\/span><b>How Often Should You Change an RO Pre-Filter?\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400;\">You will see your pre-filter turn brown. Or the water flow may drop. You need to know when the pre-filters need to be replaced based on your water source.\u00a0<\/span><\/p>\n<table>\n<tbody>\n<tr>\n<td><b>Water source<\/b><\/td>\n<td><b>How often to check the bowl<\/b><\/td>\n<td><b>Change the cartridge when<\/b><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">DJB supply only<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Once a month<\/span><\/td>\n<td><span style=\"font-weight: 400;\">It turns grey or the flow slows<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Borewell<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Every two weeks<\/span><\/td>\n<td><span style=\"font-weight: 400;\">It turns brown or orange<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400;\">Tanker or mixed tank<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Weekly, and the day after every delivery<\/span><\/td>\n<td><span style=\"font-weight: 400;\">It turns brown or the purifier fills slowly<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-weight: 400;\">A fresh cartridge can also become brown within a week or two. Your pre-filter for the water purifier is not the real problem, but your tank.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">When a filter is past its life, it becomes dirty. The cheap pre-filters are usually the first ones to go before your expectations.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">First-time water purifier owners do not realise when the pre-filters need to be replaced. This is where Rentomojo comes in. Rentomojo provides free filter changes every six months for its own purifiers. Rentomojo\u2019s plans include repairs and maintenance for the water purifiers on rent in Delhi.<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"Conclusion\"><\/span><b>Conclusion\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"font-weight: 400;\">For most households in Delhi, a carbon stage and germ protection are required. Homes on borewell water and tanker water should add a sediment pre-filter and RO on top of that. Borewell water often leaves orange marks on the taps, and the supply requires an iron filter in that case. Check the water to see whether you have the best water filters for home. Visit Rentomojo to choose a suitable water purifier for rent.\u00a0\u00a0<\/span><\/p>\n<p><strong>Also Read: <a href=\"https:\/\/www.rentomojo.com\/blog\/under-sink-vs-wall-mounted-water-purifier-in-delhi\/\">Wall Mounted vs. Under-Sink Water Purifiers in Delhi<\/a><\/strong><\/p>\n<h2><span class=\"ez-toc-section\" id=\"Frequently_Asked_Questions\"><\/span><b>Frequently Asked Questions\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"1_Which_water_filter_is_best_for_home_and_health\"><\/span><b>1. Which water filter is best for home and health?\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Choosing the water filter depends on the water source. The best water filters for home combine stages \u2013 a sediment pre-filter for sand and rust, RO for high TDS, UV or UF for bacteria, and carbon for chlorine. For households in Delhi, the DJB supply with normal TDS might require a carbon stage with UV or UF. Borewell water and tanker water sources need RO with pre-filters.\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"2_Can_we_use_RO_without_a_filter\"><\/span><b>2. Can we use RO without a filter?\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Yes, you can find an RO without an external pre-filter. RO water purifiers have built-in sediment and carbon filters that shield the membrane from grit and chlorine. For tanker or borewell water, a pre-filter for RO prevents sediment from getting through the membrane.\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"3_Can_a_pre-filter_reduce_TDS\"><\/span><b>3. Can a pre-filter reduce TDS?\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400;\">No, a pre-filter does not reduce TDS because TDS is made up of salts and minerals dissolved in water. The water needs to pass through a sediment cartridge before the RO membrane comes into play.\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"4_When_should_the_pre-filter_be_replaced\"><\/span><b>4. When should the pre-filter be replaced?\u00a0<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"font-weight: 400;\">You need to replace a water pre-filter for home when the cartridge turns brown or the purifier\u2019s flow drops. If a cartridge turns brown within a week or two, you should clean the water tank first.<\/span><span style=\"font-weight: 400;\">\u00a0<\/span><br \/>\n<script type=\"application\/ld+json\">\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Which water filter is best for home and health?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Choosing the water filter depends on the water source. The best water filters for home combine stages \u2013 a sediment pre-filter for sand and rust, RO for high TDS, UV or UF for bacteria, and carbon for chlorine. For households in Delhi, the DJB supply with normal TDS might require a carbon stage with UV or UF. 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