{"id":52676,"date":"2026-05-12T11:18:35","date_gmt":"2026-05-12T09:18:35","guid":{"rendered":"https:\/\/iwater.dk.web05.webtohosting.dk\/?p=52676"},"modified":"2026-06-18T15:01:02","modified_gmt":"2026-06-18T13:01:02","slug":"tds-maaling-er-dit-vand-beskidt-eller-bare-fyldt-med-mineraler","status":"publish","type":"post","link":"https:\/\/iwater.dk\/en\/artikel\/rent-vand\/tds-maaling-er-dit-vand-beskidt-eller-bare-fyldt-med-mineraler\/","title":{"rendered":"TDS Measurement: Is your water dirty or just full of minerals?"},"content":{"rendered":"<p class=\"wp-block-paragraph\">The answer is almost always: No. But to understand why, we need to take a look at what a TDS meter can actually do \u2013 and especially what it cannot do.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What is TDS actually?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph translation-block\"><a href=\"https:\/\/en.wikipedia.org\/wiki\/Total_dissolved_solids\" target=\"_blank\" rel=\"noopener\">TDS stands for Total Dissolved Solids<\/a>.  A TDS meter measures the electrical conductivity of the water. Since pure water (H2O) does not conduct electricity, it is the dissolved substances in the water that create the connection.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The meter converts this conductivity into a value in PPM (Parts Per Million).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><b>What does it measure?<\/b><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>Minerals: Lime (calcium), magnesium, and potassium<\/li>\n\n\n<li>Salts: Sodium, chloride, and sulphate<\/li>\n\n\n<li>Metals: Iron, copper, and lead (if present in large quantities)<\/li>\n\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><b>What does it NOT measure?<\/b><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is the most important point. A TDS meter only reacts to substances that have an electrical charge (ions). It cannot detect:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>Pesticides and herbicides: These are often organic molecules without an electrical charge<\/li>\n\n\n<li>Residues of pharmaceuticals: Such as oestrogen or painkillers<\/li>\n\n\n<li>Bacteria and viruses: Living organisms do not affect the TDS number<\/li>\n\n\n<li>Microplastics and chlorine: These are removed by a carbon filter but do not alter the TDS value<\/li>\n\n<\/ul>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>TDS measurement in connection with hydrogen therapy<\/summary>\n<p class=\"wp-block-paragraph translation-block\">This article deals exclusively with TDS measurement in connection with drinking water. TDS is also very important when it comes to <a href=\"https:\/\/iwater.dk\/en\/hydrogenterapi\/\" target=\"_self\">hydrogen therapy<\/a>, but for entirely different reasons.<\/p>\n\n\n\n<p class=\"wp-block-paragraph translation-block\">In our <a href=\"https:\/\/iwater.dk\/en\/product-category\/hydrogenterapi\/\" target=\"_self\">hydrogen therapy machines<\/a>, there are powerful electrolyzers that split the water into oxygen (O) and hydrogen (H2). In order for this process to take place as optimally as possible and give the machines the longest possible lifespan, it is important that the water added is completely pure \u2013 meaning demineralized water or distilled water. <a href=\"https:\/\/iwater.dk\/en\/product\/pure-destiller\/\" target=\"_self\">We recommend distilled water from our Pure Destiller<\/a>..<\/p>\n<\/details>\n\n\n\n<h2 class=\"wp-block-heading\">The myth of \"pure water\" (000 PPM)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Some manufacturers use a technology called ion exchange. Their filters remove minerals, lime, and salts from the water \u2013 but without demonstrating an impact on soluble substances (e.g., PFAS and pesticides). This results in a TDS measurement close to 000.<\/p>\n\n\n\n<p class=\"wp-block-paragraph translation-block\">Although it looks impressive on a meter, it does not necessarily mean that the water is \"healthier\". It simply means that the water is close to being demineralized (almost equivalent to distilled water). Many prefer water with minerals (as in  <a href=\"https:\/\/iwater.dk\/en\/product\/iwater-mosel-filterkande-filtreret-rent-og-basisk-drikkevand\/\" target=\"_self\">Mosel-pitcher<\/a>), as it gives the water character and taste, while the body benefits from the minerals.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Why does the Mosel pitcher show a higher number?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph translation-block\">Our <a href=\"https:\/\/iwater.dk\/en\/product\/iwater-mosel-filterkande-filtreret-rent-og-basisk-drikkevand\/\" target=\"_self\">Mosel pitcher<\/a> uses an active carbon filter. The primary task of the carbon filter is to remove unwanted chemicals, bad taste, chlorine, and organic contaminants through a process called adsorption.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li class=\"translation-block\"><b>The good news<\/b>: The carbon filter allows the healthy minerals (lime and magnesium) to pass through.<\/li>\n\n\n<li class=\"translation-block\"><b>The result<\/b>: Since the minerals are still in the water, your TDS meter will show almost the same number as your tap water.<\/li>\n\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph translation-block\"><b>This does not mean that the water has not been purified<\/b>. On the contrary, it means that the filter has done its job: removed the invisible chemicals but kept the minerals that are naturally found in Danish groundwater.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Experiment: Why TDS can trick you<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><b>Imagine two glasses of water:<\/b><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li>Glass A: Tap water with a TDS number of 300 (high lime content).<\/li>\n\n\n<li>Glass B: Distilled water with a TDS number of 000, but with a dangerous number of toxic pesticides added.<\/li>\n\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">If you only rely on your TDS meter, you will think that Glass B is the cleanest and healthiest. But in reality, Glass A is safe to drink, while Glass B is life-threatening.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><b>Conclusion<\/b><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A TDS meter is a tool for measuring mineral content, not a guarantee for the absence of toxins.<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"TDS m\u00e5linger - TDS fort\u00e6ller intet om graden af kemisk forurening som PFAS og pesticider\" width=\"720\" height=\"405\" src=\"https:\/\/www.youtube.com\/embed\/0qGZuv5cTjA?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Our advice to you<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If you want water that tastes good and is purified of chlorine, heavy metals, and organic impurities, but still contains nature's own minerals, then a pitcher with active carbon is the right choice.<\/p>\n\n\n\n<p class=\"wp-block-paragraph translation-block\">Do not be fooled by the TDS meter \u2013 it only tells you half of the story. Your <a href=\"https:\/\/iwater.dk\/en\/product\/iwater-mosel-filterkande-filtreret-rent-og-basisk-drikkevand\/\" target=\"_self\">Mosel-pitcher<\/a> works hard beneath the surface but does not remove the minerals your body needs.<\/p>","protected":false},"excerpt":{"rendered":"<p>Many people filter their water, and for a good reason. Many also use a small handheld TDS meter to check water quality. When the meter shows a high number for tap water or filtered water, panic often arises: \"Is my filter broken? Is the water impure?\"<\/p>","protected":false},"author":1,"featured_media":52675,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","footnotes":""},"categories":[196,197,189],"tags":[198],"ambassador_emne":[],"class_list":["post-52676","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-rent-vand","category-vand","category-videnskab","tag-vand"],"acf":[],"taxonomy_info":{"category":[{"value":196,"label":"Rent vand"},{"value":197,"label":"Vand"},{"value":189,"label":"Videnskab"}],"post_tag":[{"value":198,"label":"vand"}]},"featured_image_src_large":["https:\/\/iwater.dk\/wp-content\/uploads\/tds-maaler-i-et-glas-renset-vand_01-1024x683.avif",1024,683,true],"author_info":{"display_name":"webto","author_link":"https:\/\/iwater.dk\/en\/author\/webto\/"},"comment_info":0,"category_info":[{"term_id":196,"name":"Rent vand","slug":"rent-vand","term_group":0,"term_taxonomy_id":196,"taxonomy":"category","description":"<strong>Rent vand er vigtigt for din sundhed<\/strong>\r\nRent vand er vigtigere end nogensinde f\u00f8r. N\u00e5r du renser dit vand, minimerer du forureningen af din krop.\u00a0I Danmark oplever vi i stigende grad problemer med skadelige stoffer som PFAS i grundvandet. Derfor er der kommet meget st\u00f8rre fokus p\u00e5 kvaliteten af rent vand. Alle iWater-filtre vil rense dit vand, s\u00e5 det igen er sundt og godt at drikke.\r\n<strong>Sund vand med aktivt kul<\/strong>\r\nAlle iWater-filtre er baseret p\u00e5 aktivt kul. De renser vandet, s\u00e5 alle de gode, vigtige mineraler forbliver i vandet, mens st\u00f8rstedelen af de skadelige stoffer filtreres. Aktivt kul er 100% naturligt, og best\u00e5r oftest af br\u00e6ndte kokosskaller eller bambus. Kul har i \u00e5rhundreder v\u00e6ret brugt som vandrensning, men gennem de seneste \u00e5r er brugen af kullet blevet st\u00f8rre parallelt med, at vores behov for rensning af drikkevand er blevet st\u00f8rre, og vi \u00f8nsker at reducere brugen af plastflasker.\r\n\r\nRensning med kul og aktivt kul er baseret p\u00e5 det naturlige f\u00e6nomen, som kaldes adsorption dvs. en partikels evne til at fastholde et molekyle fanget p\u00e5 sin indre eller ydre overflade. Alle iWater-filtre s\u00f8rger for rent vand med markant reduceret m\u00e6ngder af PFAS, mikroplast, kalk, bly, kobber, klor og andre stoffer, der p\u00e5virker vandets smag. <a href=\"https:\/\/iwater.dk\/drikkevand\/\">L\u00e6s meget mere om aktivt kul her.<\/a>\r\n<strong>Rent vand giver mere energi \u2013 og smager bedre<\/strong>\r\nRent vand giver mere energi og giver os lyst til at drikke meget mere vand. Det er nemlig fri for alle de skadelig stoffer, som du kan f\u00e5 ind i kroppen, hvis du ikke renser dit vand.\u00a0Udover at vandet er sundere for din krop, s\u00e5 vil du ogs\u00e5 opleve, at det smager markant bedre. Du vil derfor lettere kunne s\u00f8rge for at give din krop al det vand, den har brug for, s\u00e5 den kan fungere optimalt og \u00f8ge din livskvalitet.","parent":0,"count":7,"filter":"raw","term_order":"0","cat_ID":196,"category_count":7,"category_description":"<strong>Rent vand er vigtigt for din sundhed<\/strong>\r\nRent vand er vigtigere end nogensinde f\u00f8r. N\u00e5r du renser dit vand, minimerer du forureningen af din krop.\u00a0I Danmark oplever vi i stigende grad problemer med skadelige stoffer som PFAS i grundvandet. Derfor er der kommet meget st\u00f8rre fokus p\u00e5 kvaliteten af rent vand. Alle iWater-filtre vil rense dit vand, s\u00e5 det igen er sundt og godt at drikke.\r\n<strong>Sund vand med aktivt kul<\/strong>\r\nAlle iWater-filtre er baseret p\u00e5 aktivt kul. De renser vandet, s\u00e5 alle de gode, vigtige mineraler forbliver i vandet, mens st\u00f8rstedelen af de skadelige stoffer filtreres. Aktivt kul er 100% naturligt, og best\u00e5r oftest af br\u00e6ndte kokosskaller eller bambus. Kul har i \u00e5rhundreder v\u00e6ret brugt som vandrensning, men gennem de seneste \u00e5r er brugen af kullet blevet st\u00f8rre parallelt med, at vores behov for rensning af drikkevand er blevet st\u00f8rre, og vi \u00f8nsker at reducere brugen af plastflasker.\r\n\r\nRensning med kul og aktivt kul er baseret p\u00e5 det naturlige f\u00e6nomen, som kaldes adsorption dvs. en partikels evne til at fastholde et molekyle fanget p\u00e5 sin indre eller ydre overflade. Alle iWater-filtre s\u00f8rger for rent vand med markant reduceret m\u00e6ngder af PFAS, mikroplast, kalk, bly, kobber, klor og andre stoffer, der p\u00e5virker vandets smag. <a href=\"https:\/\/iwater.dk\/drikkevand\/\">L\u00e6s meget mere om aktivt kul her.<\/a>\r\n<strong>Rent vand giver mere energi \u2013 og smager bedre<\/strong>\r\nRent vand giver mere energi og giver os lyst til at drikke meget mere vand. Det er nemlig fri for alle de skadelig stoffer, som du kan f\u00e5 ind i kroppen, hvis du ikke renser dit vand.\u00a0Udover at vandet er sundere for din krop, s\u00e5 vil du ogs\u00e5 opleve, at det smager markant bedre. Du vil derfor lettere kunne s\u00f8rge for at give din krop al det vand, den har brug for, s\u00e5 den kan fungere optimalt og \u00f8ge din livskvalitet.","cat_name":"Rent vand","category_nicename":"rent-vand","category_parent":0},{"term_id":197,"name":"Vand","slug":"vand","term_group":0,"term_taxonomy_id":197,"taxonomy":"category","description":"","parent":0,"count":15,"filter":"raw","term_order":"0","cat_ID":197,"category_count":15,"category_description":"","cat_name":"Vand","category_nicename":"vand","category_parent":0},{"term_id":189,"name":"Videnskab","slug":"videnskab","term_group":0,"term_taxonomy_id":189,"taxonomy":"category","description":"","parent":0,"count":10,"filter":"raw","term_order":"0","cat_ID":189,"category_count":10,"category_description":"","cat_name":"Videnskab","category_nicename":"videnskab","category_parent":0}],"tag_info":[{"term_id":198,"name":"vand","slug":"vand","term_group":0,"term_taxonomy_id":198,"taxonomy":"post_tag","description":"","parent":0,"count":11,"filter":"raw","term_order":"0"}],"_links":{"self":[{"href":"https:\/\/iwater.dk\/en\/wp-json\/wp\/v2\/posts\/52676","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iwater.dk\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/iwater.dk\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/iwater.dk\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/iwater.dk\/en\/wp-json\/wp\/v2\/comments?post=52676"}],"version-history":[{"count":2,"href":"https:\/\/iwater.dk\/en\/wp-json\/wp\/v2\/posts\/52676\/revisions"}],"predecessor-version":[{"id":54429,"href":"https:\/\/iwater.dk\/en\/wp-json\/wp\/v2\/posts\/52676\/revisions\/54429"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/iwater.dk\/en\/wp-json\/wp\/v2\/media\/52675"}],"wp:attachment":[{"href":"https:\/\/iwater.dk\/en\/wp-json\/wp\/v2\/media?parent=52676"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/iwater.dk\/en\/wp-json\/wp\/v2\/categories?post=52676"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/iwater.dk\/en\/wp-json\/wp\/v2\/tags?post=52676"},{"taxonomy":"ambassador_emne","embeddable":true,"href":"https:\/\/iwater.dk\/en\/wp-json\/wp\/v2\/ambassador_emne?post=52676"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}