{"product_id":"hanna-groline-ph-4-01-calibration-buffer-500-ml","title":"Hanna GroLine pH 4.01 Calibration Buffer — 500 mL","description":"\u003cp\u003epH 4.01 is the acidic calibration point used to set the slope in a two-point calibration — essential for accurate readings in the 5.5–6.5 range most nutrient solutions run at. This 500 mL bottle of GroLine buffer suits growers who calibrate often.\u003c\/p\u003e\n\u003cp\u003eHanna calibration buffers are prepared to precise formulas and standardized against NIST-traceable reference standards, so your meter reads true every time you calibrate. Each container is airtight with a tamper-proof seal, and the lot number and expiration date are printed on the label. Unopened, Hanna buffers carry a 5-year shelf life.\u003c\/p\u003e","brand":"Hanna Instruments","offers":[{"title":"Default Title","offer_id":54278739624219,"sku":"HI7004L","price":26.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0708\/6768\/1563\/files\/hi7004l_91746fe8-4e28-4ad2-872a-a139dc984f37.webp?v=1792257177","url":"https:\/\/ghhydro.com\/products\/hanna-groline-ph-4-01-calibration-buffer-500-ml","provider":"Green Harvest Hydroponics","version":"1.0","type":"link"}