{"product_id":"hanna-hi783-25-marine-magnesium-reagents","title":"Hanna HI783-25 Marine Magnesium Reagents, 25 Tests","description":"\u003cdiv id=\"bts-hi783-25-description\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;max-width:1400px;margin:0 auto;padding:20px 12px;color:#26332C;background:#fff;\"\u003e\n\u003cdiv style=\"display:flex;flex-wrap:wrap;align-items:center;gap:20px;padding-bottom:20px;margin-bottom:24px;border-bottom:1px solid #e0e0e0;\"\u003e\n\u003cdiv style=\"flex:1 1 360px;min-width:0;box-sizing:border-box;\"\u003e\n\u003ch4 style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;font-weight:400;line-height:1.35;margin:0 0 16px;color:#245B45;\"\u003eKeep reef magnesium checks matched to marine chemistry\u003c\/h4\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;margin:0 0 16px;\"\u003eReplenish your HI783 Checker or the documented HI83399 marine magnesium method without replacing the meter. This 25-test refill is designed for magnesium concentrations typical of saltwater aquarium monitoring, with a direct magnesium-ion result rather than a hardness value.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cfigure style=\"flex:0 1 310px;min-width:0;margin:0;text-align:center;box-sizing:border-box;\"\u003e\n\u003cimg alt=\"Hanna HI783-25 manufacturer reagent refill photograph\" height=\"1200\" loading=\"lazy\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/HI783-25_720x720__93332.1667498879.jpg?v=1793900648\" style=\"width:100%;max-width:300px;height:auto;object-fit:contain;\" width=\"1200\"\u003e\n\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;font-size:0.9rem;margin-top:8px;\"\u003eManufacturer photograph of the marine reagent refill; packaging shown is representative.\u003c\/figcaption\u003e\u003c\/figure\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#F1F7F3;border-left:3px solid #245B45;padding:20px;box-sizing:border-box;margin:0 0 24px;\"\u003e\n\u003ch4 style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;font-weight:400;line-height:1.35;margin:0 0 16px;color:#245B45;\"\u003eSelect the right method\u003c\/h4\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;margin:0 0 16px;\"\u003eChoose this refill for marine magnesium at 1000–1800: ppm as Mg²⁺ on HI783, or mg\/L as Mg²⁺ on the HI83399 Marine Magnesium method. It is not freshwater magnesium chemistry from the HI93752 family or HI93719 magnesium-hardness reagent.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch4 style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;font-weight:400;line-height:1.35;margin:0 0 16px;color:#245B45;\"\u003eA 25-test refill for ongoing marine monitoring\u003c\/h4\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;margin:0 0 16px;\"\u003eHI783A-0 Marine Magnesium Reagent A and HI783IND-0 indicator provide the matched chemistry for 25 tests. Replenish your existing setup for repeat marine magnesium checks; repeats and quality-control tests also use reagent capacity.\u003c\/p\u003e\n\u003ch4 style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;font-weight:400;line-height:1.35;margin:0 0 16px;color:#245B45;\"\u003eDedicated tools support consistent measurements\u003c\/h4\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;margin:0 0 16px;\"\u003eAccurate dosing depends on separate, clean and dry 5 mL syringes with their matching tips: black printing for reagent A and blue printing for the marine sample. Keep each syringe dedicated to its role; the linked instrument manuals provide the full dosing and reading procedure.\u003c\/p\u003e\n\u003ch4 style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;font-weight:400;line-height:1.35;margin:0 0 16px;color:#245B45;\"\u003eCheck temperature and calcium fit\u003c\/h4\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;margin:0 0 16px;\"\u003eFor the documented HI783 Checker and HI83399 Marine Magnesium methods, keep the prepared cuvette (sample plus reagents) at 22–28 °C and hold it by the cap to avoid warming the glass. Calcium below 300 or above 500 mg\/L can interfere, so check sample composition before choosing this method for an unusual marine matrix.\u003c\/p\u003e\n\u003ch4 style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;font-weight:400;line-height:1.35;margin:0 0 16px;color:#245B45;\"\u003eUse the named marine magnesium method\u003c\/h4\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;margin:0 0 16px;\"\u003eHI783 Checker specifies 1000–1800 ppm as Mg²⁺ with 5 ppm resolution and a 610 nm LED. The documented HI83399 Marine Magnesium method specifies 1000–1800 mg\/L as Mg²⁺ with 5 mg\/L resolution and 640 nm optics. Use each instrument’s own method and specifications—not a generic magnesium or hardness program.\u003c\/p\u003e\n\u003ch4 style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;font-weight:400;line-height:1.35;margin:0 0 16px;color:#245B45;\"\u003eReady your reusable equipment\u003c\/h4\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;margin:0 0 16px;\"\u003eHave the compatible instrument, clean cuvette and cap, dedicated syringes and tips, scissors, lint-free cleaning materials and RODI water for rinsing ready separately. RODI rinsing and keeping reagent and sample tips separate help avoid contamination; do not rinse with tank water. This reagent refill is not an instrument starter kit.\u003c\/p\u003e\n\u003ch4 style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;font-weight:400;line-height:1.35;margin:0 0 16px;color:#245B45;\"\u003ePractical handling\u003c\/h4\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;font-size:1rem;line-height:1.65;box-sizing:border-box;margin:0 0 16px;\"\u003eWear the protective equipment specified in the component SDS, avoid contact with reagents and dispose of used solutions according to the SDS and local requirements. Check the supplied lot label and component SDS before use.\u003c\/p\u003e\n\n\n\u003cdiv class=\"faq_block\" style=\"border-top:1px solid #e0e0e0;margin-top:24px;\"\u003e\u003cdiv itemscope=\"\" itemtype=\"https:\/\/schema.org\/FAQPage\" style=\"width: 100%; padding: 20px 0; font-family: 'Open Sans', sans-serif; font-weight: 300; color: #333;line-height:1.15;\"\u003e\n\u003ch3 style=\"font-size:1.1rem;font-weight:400;margin:0 0 16px;color:#245B45;\"\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cdetails itemprop=\"mainEntity\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Question\" style=\"border: 1px solid #e0e0e0; border-radius: 8px; margin: 0 0 10px 0; background: #fff;\"\u003e\u003csummary itemprop=\"name\" style=\"cursor: pointer; padding: 14px 16px; font-size: 1rem; font-weight: 400; list-style-position: inside;\"\u003eWhen should I choose HI783-25?\u003c\/summary\u003e\u003cdiv itemprop=\"acceptedAnswer\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Answer\" style=\"padding: 0 16px 14px 16px;\"\u003e\u003cp itemprop=\"text\" style=\"font-size: 0.97rem; line-height: 1.6; margin: 0;\"\u003eChoose it to replenish an HI783 Marine Magnesium Checker or the directly documented HI83399 Marine Magnesium method when your marine sample is within 1000–1800 on the instrument’s stated magnesium-ion scale.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails itemprop=\"mainEntity\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Question\" style=\"border: 1px solid #e0e0e0; border-radius: 8px; margin: 0 0 10px 0; background: #fff;\"\u003e\u003csummary itemprop=\"name\" style=\"cursor: pointer; padding: 14px 16px; font-size: 1rem; font-weight: 400; list-style-position: inside;\"\u003eDoes the result mean magnesium hardness as CaCO₃?\u003c\/summary\u003e\u003cdiv itemprop=\"acceptedAnswer\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Answer\" style=\"padding: 0 16px 14px 16px;\"\u003e\u003cp itemprop=\"text\" style=\"font-size: 0.97rem; line-height: 1.6; margin: 0;\"\u003eNo. HI783 reports ppm as Mg²⁺ and HI83399 reports mg\/L as Mg²⁺. This is not a magnesium-hardness result as CaCO₃ and should not be relabeled as one.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails itemprop=\"mainEntity\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Question\" style=\"border: 1px solid #e0e0e0; border-radius: 8px; margin: 0 0 10px 0; background: #fff;\"\u003e\u003csummary itemprop=\"name\" style=\"cursor: pointer; padding: 14px 16px; font-size: 1rem; font-weight: 400; list-style-position: inside;\"\u003eCan I use it instead of HI93752 or HI93719 reagents?\u003c\/summary\u003e\u003cdiv itemprop=\"acceptedAnswer\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Answer\" style=\"padding: 0 16px 14px 16px;\"\u003e\u003cp itemprop=\"text\" style=\"font-size: 0.97rem; line-height: 1.6; margin: 0;\"\u003eNo substitution is established. The HI93752 family’s freshwater magnesium method and HI93719 magnesium-hardness method answer different measurement questions. Use this set only with its documented marine method.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails itemprop=\"mainEntity\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Question\" style=\"border: 1px solid #e0e0e0; border-radius: 8px; margin: 0 0 10px 0; background: #fff;\"\u003e\u003csummary itemprop=\"name\" style=\"cursor: pointer; padding: 14px 16px; font-size: 1rem; font-weight: 400; list-style-position: inside;\"\u003eWhy does prepared-sample temperature matter?\u003c\/summary\u003e\u003cdiv itemprop=\"acceptedAnswer\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Answer\" style=\"padding: 0 16px 14px 16px;\"\u003e\u003cp itemprop=\"text\" style=\"font-size: 0.97rem; line-height: 1.6; margin: 0;\"\u003eThe marine procedure requires the sample-plus-reagent cuvette to be 22–28 °C. Warm or cool the prepared cuvette as needed and hold it by the cap; warming the glass with your hands can affect accuracy.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails itemprop=\"mainEntity\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Question\" style=\"border: 1px solid #e0e0e0; border-radius: 8px; margin: 0 0 10px 0; background: #fff;\"\u003e\u003csummary itemprop=\"name\" style=\"cursor: pointer; padding: 14px 16px; font-size: 1rem; font-weight: 400; list-style-position: inside;\"\u003eCan calcium affect a marine magnesium result?\u003c\/summary\u003e\u003cdiv itemprop=\"acceptedAnswer\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Answer\" style=\"padding: 0 16px 14px 16px;\"\u003e\u003cp itemprop=\"text\" style=\"font-size: 0.97rem; line-height: 1.6; margin: 0;\"\u003eYes. Calcium below 300 or above 500 mg\/L is a listed interference. Check your sample and the complete method guidance rather than assuming all saltwater compositions are suitable.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails itemprop=\"mainEntity\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Question\" style=\"border: 1px solid #e0e0e0; border-radius: 8px; margin: 0 0 10px 0; background: #fff;\"\u003e\u003csummary itemprop=\"name\" style=\"cursor: pointer; padding: 14px 16px; font-size: 1rem; font-weight: 400; list-style-position: inside;\"\u003eAre the HI783 and HI83399 optical specifications the same?\u003c\/summary\u003e\u003cdiv itemprop=\"acceptedAnswer\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Answer\" style=\"padding: 0 16px 14px 16px;\"\u003e\u003cp itemprop=\"text\" style=\"font-size: 0.97rem; line-height: 1.6; margin: 0;\"\u003eNo. The HI783 uses 610 nm, while HI83399 §9.50 specifies 640 nm. Compatibility is established by their named methods and exact reagent listing, not by treating one wavelength as universal.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails itemprop=\"mainEntity\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Question\" style=\"border: 1px solid #e0e0e0; border-radius: 8px; margin: 0 0 10px 0; background: #fff;\"\u003e\u003csummary itemprop=\"name\" style=\"cursor: pointer; padding: 14px 16px; font-size: 1rem; font-weight: 400; list-style-position: inside;\"\u003eWhat reusable tools do I need?\u003c\/summary\u003e\u003cdiv itemprop=\"acceptedAnswer\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Answer\" style=\"padding: 0 16px 14px 16px;\"\u003e\u003cp itemprop=\"text\" style=\"font-size: 0.97rem; line-height: 1.6; margin: 0;\"\u003eHave a compatible meter, clean dry cuvette and cap, two dedicated 5 mL syringes with their correct tips, scissors and cleaning materials ready separately. Keep the black-print reagent syringe separate from the blue-print sample syringe, and use RODI water for rinsing.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails itemprop=\"mainEntity\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Question\" style=\"border: 1px solid #e0e0e0; border-radius: 8px; margin: 0 0 10px 0; background: #fff;\"\u003e\u003csummary itemprop=\"name\" style=\"cursor: pointer; padding: 14px 16px; font-size: 1rem; font-weight: 400; list-style-position: inside;\"\u003eHow should I plan for the 25-test capacity?\u003c\/summary\u003e\u003cdiv itemprop=\"acceptedAnswer\" itemscope=\"\" itemtype=\"https:\/\/schema.org\/Answer\" style=\"padding: 0 16px 14px 16px;\"\u003e\u003cp itemprop=\"text\" style=\"font-size: 0.97rem; line-height: 1.6; margin: 0;\"\u003eHanna states capacity for 25 tests; repeats and quality-control checks consume that capacity too. This is a test-capacity rating, not a count of bottles or packets. The factory photograph shows representative packaging; use the supplied lot label for expiry information.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\n\u003c\/div\u003e\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Hanna Instruments","offers":[{"title":"Default Title","offer_id":53467987280170,"sku":"BTS-HI783-25","price":28.59,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/HI783-25_720x720__93332.1667498879.jpg?v=1793900648","url":"https:\/\/bluetigerscientific.com\/products\/hanna-hi783-25-marine-magnesium-reagents","provider":"Blue Tiger Scientific","version":"1.0","type":"link"}