{"product_id":"bluelab-ph-4-buffer-low-range-calibration","title":"Bluelab pH 4.0 Calibration Solution","description":"\u003ch4\u003e\u003cbr\u003e\u003c\/h4\u003e\n\u003ch2\u003eBluelab pH 4.0 Calibration Solution\u003c\/h2\u003e\n\u003cdiv\u003e\n\u003cp\u003eA pH meter that hasn't been calibrated recently can drift silently off target, throwing off nutrient decisions before you notice anything's wrong. Bluelab pH 4.0 Calibration Solution solves this by giving your \u003ca href=\"\/products\/bluelab-ph-pen-compact-ph-temp-reader-floats\"\u003eBluelab pH Pen\u003c\/a\u003e or meter a known reference point to calibrate against, keeping readings accurate and dependable.\u003c\/p\u003e\n\u003cp\u003eRegular cleaning and calibration boost the longevity of your \u003ca href=\"\/products\/bluelab-ph-probe-double-junction-bnc-connector\"\u003epH probes\u003c\/a\u003e, and the pH 4.0 solution is a core part of that routine — a must-have in every grower's maintenance toolbox alongside \u003ca href=\"\/products\/bluelab-ph-7-buffer-neutral-point-calibration\"\u003eBluelab pH 7.0 Calibration Solution\u003c\/a\u003e for standard 2-point calibration.\u003c\/p\u003e\n\u003cp\u003eSold exclusively in box-of-6 case packs, available in 250ml (8.4fl.oz.) or 500ml bottle sizes — choose the size that matches your usage and restocking needs from the size selector.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch4\u003eFeatures\u003c\/h4\u003e\n\u003cstyle\u003e.features-grid-container{display:flex;flex-wrap:wrap;justify-content:center;gap:1rem;padding:2rem 0;font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;margin:0 auto;max-width:1240px;}.feature-card{background-color:transparent;padding:1.5rem;border-radius:8px;text-align:center;flex:0 1 280px;box-sizing:border-box;}\u003c\/style\u003e\n\u003cdiv class=\"features-grid-container\"\u003e\n\u003cdiv class=\"feature-card\"\u003e\n\u003cspan style=\"font-size: 2.5em; line-height: 1; color: #2c5530;\"\u003e🎯\u003c\/span\u003e\n\u003ch5 style=\"font-size: 1.1em; font-weight: bold; color: #333; margin: 0.75rem 0 0.5rem 0;\"\u003eAccurate pH Calibration\u003c\/h5\u003e\n\u003cp style=\"font-size: 0.95em; line-height: 1.6; color: #555; margin: 0;\"\u003eA known 4.0 pH reference point keeps your meter reading true.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"feature-card\"\u003e\n\u003cspan style=\"font-size: 2.5em; line-height: 1; color: #2c5530;\"\u003e🔧\u003c\/span\u003e\n\u003ch5 style=\"font-size: 1.1em; font-weight: bold; color: #333; margin: 0.75rem 0 0.5rem 0;\"\u003eExtends Probe Longevity\u003c\/h5\u003e\n\u003cp style=\"font-size: 0.95em; line-height: 1.6; color: #555; margin: 0;\"\u003eRegular calibration and cleaning with \u003ca href=\"\/products\/bluelab-kcl-storage-solution-keep-probes-hydrated\"\u003estorage solution\u003c\/a\u003e keep your pH probe performing longer.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"feature-card\"\u003e\n\u003cspan style=\"font-size: 2.5em; line-height: 1; color: #2c5530;\"\u003e📦\u003c\/span\u003e\n\u003ch5 style=\"font-size: 1.1em; font-weight: bold; color: #333; margin: 0.75rem 0 0.5rem 0;\"\u003eBox-of-6 Case Packs\u003c\/h5\u003e\n\u003cp style=\"font-size: 0.95em; line-height: 1.6; color: #555; margin: 0;\"\u003eAvailable in 250ml and 500ml bottle sizes, sold by the case.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch4 style=\"margin-bottom: 0;\"\u003eSpecifications\u003c\/h4\u003e\n\u003cstyle\u003e.styled-spec-container{width:100%;overflow-x:auto;-webkit-overflow-scrolling:touch;border:1px solid #eee;border-radius:8px;margin-bottom:1em;}.styled-spec-table{width:100%;border-collapse:collapse;}.styled-spec-table thead{background-color:#f8f8f8;}.styled-spec-table th,.styled-spec-table td{padding:12px 15px;text-align:left;vertical-align:top;}.styled-spec-table th{font-weight:bold;color:#333;border-bottom:2px solid #ccc;}.styled-spec-table td{border-bottom:1px solid #eee;}.styled-spec-table tbody td:first-child{font-weight:500;color:#444;}.styled-spec-table tbody tr:last-child td{border-bottom:none;}\u003c\/style\u003e\n\u003cdiv class=\"styled-spec-container\"\u003e\n\u003ctable class=\"styled-spec-table\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eOption\u003c\/th\u003e\n\u003cth\u003eVolume\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eCase Pack\u003c\/td\u003e\n\u003ctd\u003eBox of 6 — 250ml bottles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCase Pack\u003c\/td\u003e\n\u003ctd\u003eBox of 6 — 500ml bottles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003ch4\u003eFrequently Asked Questions\u003c\/h4\u003e\n\u003cdiv class=\"faq-container\"\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cdiv class=\"faq-question\"\u003e\n\u003cspan\u003eWhat is pH 4.0 Calibration Solution used for?\u003c\/span\u003e\u003cspan class=\"faq-icon\"\u003e+\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-answer\"\u003e\n\u003cdiv\u003e\n\u003cp\u003eIt's a known reference solution used to calibrate your pH meter or pen, ensuring readings stay accurate over time.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cdiv class=\"faq-question\"\u003e\n\u003cspan\u003eDo I need both pH 4.0 and pH 7.0 solutions?\u003c\/span\u003e\u003cspan class=\"faq-icon\"\u003e+\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-answer\"\u003e\n\u003cdiv\u003e\n\u003cp\u003eYes. Standard 2-point calibration uses both pH 4.0 and \u003ca href=\"\/products\/bluelab-ph-7-buffer-neutral-point-calibration\"\u003epH 7.0 solutions\u003c\/a\u003e together to ensure accuracy across your meter's full range.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cdiv class=\"faq-question\"\u003e\n\u003cspan\u003eWhat sizes are available?\u003c\/span\u003e\u003cspan class=\"faq-icon\"\u003e+\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-answer\"\u003e\n\u003cdiv\u003e\n\u003cp\u003eIt's sold in box-of-6 case packs, available in either 250ml or 500ml bottle sizes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cdiv class=\"faq-question\"\u003e\n\u003cspan\u003eHow often should I calibrate my pH meter?\u003c\/span\u003e\u003cspan class=\"faq-icon\"\u003e+\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-answer\"\u003e\n\u003cdiv\u003e\n\u003cp\u003eRegular calibration helps extend the life and accuracy of your probe — check your specific meter's manual for a recommended schedule.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cdiv class=\"faq-question\"\u003e\n\u003cspan\u003eCan I buy a single bottle instead of a case?\u003c\/span\u003e\u003cspan class=\"faq-icon\"\u003e+\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-answer\"\u003e\n\u003cdiv\u003e\n\u003cp\u003eNo — this solution is now sold exclusively in box-of-6 case packs, available in 250ml or 500ml bottle sizes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Bluelab","offers":[{"title":"250 ml - Box of 6","offer_id":52495699411160,"sku":"PH4250BL","price":89.0,"currency_code":"USD","in_stock":true},{"title":"500 ml - Box of 6","offer_id":52495699443928,"sku":"PH4500BL","price":145.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1383\/1731\/files\/Bluelab_pH_4_Calibration_Solution_250ml.webp?v=1789748795","url":"https:\/\/trimleaf.com\/products\/bluelab-ph-4-buffer-low-range-calibration","provider":"Trimleaf","version":"1.0","type":"link"}