[{"data":1,"prerenderedAt":194},["ShallowReactive",2],{"\u002Fwater-filters\u002Ftools":3,"type-articles-\u002Fwater-filters\u002Ftools":154,"related-\u002Fwater-filters\u002Ftools":162},{"id":4,"title":5,"body":6,"date":144,"description":145,"extension":146,"meta":147,"navigation":148,"path":149,"seo":150,"silo":151,"stem":152,"__hash__":153},"content\u002Fwater-filters\u002Ftools\u002Findex.md","Water Filter Tools: Diagnose Before You Buy",{"type":7,"value":8,"toc":136},"minimark",[9,13,24,50,53,56,64,71,100,104,112,124,132],[10,11,12],"p",{},"A filter takes five minutes to buy, but a good purchase starts with a diagnosis: what is actually in your water? The answer is almost always available for free — it just takes knowing where to look. The tools in this section exist for that: put numbers on your water before spending a dollar, so you buy the right level of treatment.",[14,15,17,23],"h2",{"id":16},"your-utilitys-report-the-first-move",[18,19],"icon",{"className":20,"name":22},[21],"size-6","solar:document-text-bold-duotone"," Your utility's report: the first move",[10,25,26,27,32,33,37,38,41,42,45,46,49],{},"Every community water system publishes an annual Consumer Confidence Report, and the results are public. You do not have to go hunting for it: I republish them city by city in ",[28,29,31],"a",{"href":30},"\u002Fwater-quality","the water quality register",". The lines that matter for choosing a filter are the ",[34,35,36],"strong",{},"chlorine residual"," (the one responsible for the taste), ",[34,39,40],{},"lead"," and ",[34,43,44],{},"PFAS"," (which need certification or reverse osmosis, not a taste filter), and ",[34,47,48],{},"disinfection byproducts",".",[51,52],"water-quality-widget",{},[10,54,55],{},"Five minutes of reading saves you from the two symmetrical mistakes: over-equipping water that only needed activated carbon, or under-equipping water that deserved better.",[14,57,59,63],{"id":58},"hardness-the-one-figure-your-report-probably-omits",[18,60],{"className":61,"name":62},[21],"solar:test-tube-bold-duotone"," Hardness: the one figure your report probably omits",[10,65,66,67,70],{},"Second reflex, and the one that surprises people: ",[34,68,69],{},"hardness is usually not in the report",". It is not a regulated contaminant, so most utilities never publish it — roughly three reports in four skip it. Where it exists, this site shows it in grains per gallon. Where it does not, a test strip settles it in ten seconds.",[10,72,73,74,77,78,81,82,85,86,89,90,94,95,99],{},"The scale: under ",[34,75,76],{},"3.5 gpg"," soft, ",[34,79,80],{},"3.5 to 7"," moderately hard, ",[34,83,84],{},"7 to 10.5"," hard, over ",[34,87,88],{},"10.5"," very hard. This number decides a whole side of your equipment: on very hard water, your white deposits are scale and no carbon filter will change that; on soft water, forget the softener. The method is in ",[28,91,93],{"href":92},"\u002Fwater-filters\u002Ftools\u002Ftest-water-hardness-at-home","how to test your water hardness at home",", and ",[28,96,98],{"href":97},"\u002Fwater-filters\u002Ftools\u002Fwater-hardness-by-city","water hardness by city"," explains where the published figures come from and why they are patchy.",[101,102],"affiliation-box",{"id":103},"hardness-test-strips",[14,105,107,111],{"id":106},"cost-per-gallon-the-calculation-that-settles-everything",[18,108],{"className":109,"name":110},[21],"solar:wallet-money-bold-duotone"," Cost per gallon: the calculation that settles everything",[10,113,114,115,118,119,123],{},"To compare a pitcher, a faucet mount and an under-sink unit on the same basis, one calculation: ",[34,116,117],{},"cartridge price divided by its rated capacity in gallons",". A pitcher cartridge ($7 for about 40 gallons) works out at roughly 17 cents a gallon; a faucet cartridge ($20 for 100 gallons) around 20 cents; an under-sink block ($49 for 1,000 gallons) under 5 cents. Bottled water sits between $1 and $2. Run this before every purchase, taking 20 to 30% off the rated capacities to match real use: the rankings in the ",[28,120,122],{"href":121},"\u002Fwater-filters\u002Fcomparisons","comparisons"," are built on it.",[14,125,127,131],{"id":126},"frequently-asked-questions",[18,128],{"className":129,"name":130},[21],"solar:question-circle-bold-duotone"," Frequently asked questions",[133,134],"faq",{":items":135},"[{\"q\":\"How do I find out the quality of my city's water?\",\"a\":\"Enter your city in the register: I republish what your utility reported — chlorine, lead, PFAS, nitrate, arsenic, disinfection byproducts and bacteria — taken from its own annual Consumer Confidence Report.\",\"href\":\"\u002Fwater-quality\",\"linkText\":\"See your city's report\"},{\"q\":\"What does filtered water cost per gallon?\",\"a\":\"Roughly 20 cents a gallon for a faucet filter, 17 for a pitcher, and under 5 for a long-life under-sink block, against $1 to $2 for bottled water. Divide the cartridge price by its real capacity to get your own figure.\"},{\"q\":\"Does hardness change which filter I should buy?\",\"a\":\"Yes, in the negative: if your water is very hard, no carbon filter will reduce the scale. The filter stays useful for taste, but protecting the house goes through a softener.\",\"href\":\"\u002Fwater-filters\u002Ftools\u002Fwater-hardness-by-city\",\"linkText\":\"Understanding hardness by city\"}]",{"title":137,"searchDepth":138,"depth":138,"links":139},"",2,[140,141,142,143],{"id":16,"depth":138,"text":23},{"id":58,"depth":138,"text":63},{"id":106,"depth":138,"text":111},{"id":126,"depth":138,"text":131},"2026-08-03","My tools for sizing up your water before spending a dollar: your utility's report, testing hardness yourself, and the cost-per-gallon calculation that settles every comparison.","md",{},true,"\u002Fwater-filters\u002Ftools",{"title":5,"description":145},"water-filters","water-filters\u002Ftools\u002Findex","vHsHI9Km3FWQ6KTbdQnw0FTHJevLRvbTxAc_dpxhaHU",[155,159],{"path":92,"title":156,"description":157,"date":158},"How to Test Your Water Hardness at Home","Test strips, titration kits or a TDS meter: the three ways to measure water hardness at home, how accurate each really is, and the ppm-versus-grains trap.","2026-08-04",{"path":97,"title":160,"description":161,"date":144},"Water Hardness by City: Why Your Report Probably Doesn't List It","Finding your water hardness in grains per gallon: what utilities publish and what they leave out, why most reports skip hardness, and how to get the number anyway.",{"overview":163,"articles":167},{"path":164,"title":165,"description":166},"\u002Fwater-filters","Water Filters: Which One to Choose in 2026","Pitcher, faucet mount or under-sink: which water filter to pick to improve your tap water, what it costs, and what it really does to the taste.",[168,171,175,179,183,187,191,192,193],{"path":121,"title":169,"description":170,"date":144},"Water Filter Comparisons: My Method and My Head-to-Heads","How I compare water filters: cost per gallon, filtration grade, real flow rate and certification — beyond 'removes chlorine, improves taste'.",{"path":172,"title":173,"description":174,"date":158},"\u002Fwater-filters\u002Fcomparisons\u002Funder-sink-water-filters","Which Under-Sink Water Filter to Choose in 2026","Under-sink filters: real cartridge capacity, cost per gallon, installation, and the difference with reverse osmosis. The models I would pick, and for what.",{"path":176,"title":177,"description":178,"date":158},"\u002Fwater-filters\u002Fguides\u002Fchlorine-taste-tap-water","Chlorine Taste in Tap Water: Where It Comes From, How to Get Rid of It","Why your tap water tastes like a swimming pool, what that says about its quality, and the fixes that actually work — from a pitcher to an under-sink filter.",{"path":180,"title":181,"description":182,"date":144},"\u002Fwater-filters\u002Fguides","Water Filters: The 3 Questions to Settle Before Buying","Diagnosis, format, upkeep: my water filter buying guides, in the order the questions come up before you reach for a card.",{"path":184,"title":185,"description":186,"date":158},"\u002Fwater-filters\u002Freviews\u002Fbrita-faucet-filter-review","PUR PLUS Faucet Filter Review: What It Really Does","A review of the PUR PLUS faucet mount: what it actually filters, its real cost per gallon, the faucet compatibility question, and the alternatives.",{"path":188,"title":189,"description":190,"date":144},"\u002Fwater-filters\u002Freviews","Water Filter Reviews: How I Judge Them","How I build my water filter reviews: the verifiable criteria, the traps in online reviews, and what only shows up after months of use.",{"path":149,"title":5,"description":145,"date":144},{"path":92,"title":156,"description":157,"date":158},{"path":97,"title":160,"description":161,"date":144},1787678118419]