{"product_id":"fritz-rpm-liquid-pt-3-magnesium-reef-supplement","title":"Fritz RPM Liquid PT 3 Magnesium | Reef Magnesium Supplement for SPS, LPS \u0026 Soft Corals","description":"\u003cstyle\u003e\n  .aq-pd { font-family: Georgia, serif; color: #1a1a1a; max-width: 860px; margin: 0 auto; line-height: 1.7; }\n  .aq-pd h2 { font-size: 1.45em; font-weight: 700; letter-spacing: -0.01em; border-left: 4px solid #FF5722; padding-left: 12px; margin: 2em 0 0.6em; }\n  .aq-pd h3 { font-size: 1.05em; font-weight: 700; margin: 1.2em 0 0.4em; color: #FF5722; text-transform: uppercase; letter-spacing: 0.06em; font-family: Arial, sans-serif; }\n  .aq-pd p { margin: 0.5em 0 1em; }\n  .aq-callout { background: #1a1a1a; color: #fff; border-radius: 4px; padding: 16px 20px; margin: 1.6em 0; font-family: Arial, sans-serif; font-size: 0.93em; line-height: 1.6; }\n  .aq-callout strong { color: #f5c518; }\n  .aq-features { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; margin: 1em 0 1.6em; }\n  .aq-feature-card { background: #f4f4f4; border-radius: 4px; padding: 14px 16px; border-left: 3px solid #FF5722; font-family: Arial, sans-serif; font-size: 0.9em; }\n  .aq-feature-card strong { display: block; margin-bottom: 3px; color: #1a1a1a; }\n  .aq-feature-card span { color: #555; }\n  .aq-compare { overflow-x: auto; margin: 1em 0 1.6em; }\n  .aq-compare table { width: 100%; border-collapse: collapse; font-family: Arial, sans-serif; font-size: 0.88em; min-width: 520px; }\n  .aq-compare th { background: #FF5722; color: #fff; padding: 9px 14px; text-align: center; font-weight: 700; letter-spacing: 0.05em; text-transform: uppercase; }\n  .aq-compare th:first-child { background: #1a1a1a; text-align: left; }\n  .aq-compare td { padding: 8px 14px; border-bottom: 1px solid #ddd; text-align: center; }\n  .aq-compare td:first-child { text-align: left; font-weight: 600; color: #444; background: #fafafa; }\n  .aq-compare tr:nth-child(even) td:not(:first-child) { background: #fff8f8; }\n  .aq-check { color: #27ae60; font-weight: 700; }\n  .aq-dash { color: #bbb; }\n  .aq-specs-table { width: 100%; border-collapse: collapse; margin-top: 1em; font-family: Arial, sans-serif; font-size: 0.93em; }\n  .aq-specs-table th { background: #1a1a1a; color: #fff; text-align: left; padding: 9px 14px; font-weight: 600; letter-spacing: 0.04em; text-transform: uppercase; font-size: 0.82em; }\n  .aq-specs-table td { padding: 8px 14px; border-bottom: 1px solid #e5e5e5; vertical-align: top; }\n  .aq-specs-table tr:nth-child(even) td { background: #f9f9f9; }\n  .aq-specs-table td:first-child { font-weight: 600; width: 45%; color: #444; }\n  .aq-tab-radio { display: none; }\n  .aq-tab-labels { display: flex; flex-wrap: wrap; gap: 8px; margin: 1.4em 0 0; }\n  .aq-tab-label { display: inline-block; padding: 10px 22px; border: 2px solid #FF5722; background: #fff; color: #FF5722; font-weight: 700; font-family: Arial, sans-serif; font-size: 0.9em; cursor: pointer; border-radius: 3px; letter-spacing: 0.04em; transition: background 0.15s, color 0.15s; user-select: none; }\n  .aq-tab-label:hover { background: #ffd7c2; }\n  .aq-tab-panel { display: none; }\n  #aq-tab-16:checked ~ .aq-tab-labels label[for=\"aq-tab-16\"],\n  #aq-tab-32:checked ~ .aq-tab-labels label[for=\"aq-tab-32\"],\n  #aq-tab-1g:checked ~ .aq-tab-labels label[for=\"aq-tab-1g\"],\n  #aq-tab-5g:checked ~ .aq-tab-labels label[for=\"aq-tab-5g\"] { background: #FF5722; color: #fff; }\n  #aq-tab-16:checked ~ .aq-panels #aq-panel-16,\n  #aq-tab-32:checked ~ .aq-panels #aq-panel-32,\n  #aq-tab-1g:checked ~ .aq-panels #aq-panel-1g,\n  #aq-tab-5g:checked ~ .aq-panels #aq-panel-5g { display: block; }\n  .aq-note { font-family: Arial, sans-serif; font-size: 0.82em; color: #777; margin-top: -0.5em; font-style: italic; }\n\u003c\/style\u003e\n\n\u003cdiv class=\"aq-pd\"\u003e\n\n  \u003cp\u003e\u003cstrong\u003eFritz RPM Liquid PT 3 Magnesium\u003c\/strong\u003e is the magnesium component of the Fritz \u003cem\u003eReef Pro Mineral\u003c\/em\u003e dosing system. Stable magnesium (Mg) levels keep calcium and alkalinity from precipitating out of solution, which is why Mg is the unsung hero of every successful reef tank. Pharmaceutical-grade and made in the USA, PT 3 delivers a clean, predictable boost any time Mg trends below the reef-safe range.\u003c\/p\u003e\n\n  \u003cp\u003eDose alongside \u003cstrong\u003eRPM PT 1 (Alkalinity)\u003c\/strong\u003e and \u003cstrong\u003ePT 2 (Calcium)\u003c\/strong\u003e for full reef chemistry support, and verify levels with a precision test kit like the \u003ca href=\"https:\/\/squeakysaquatics.com\/products\/salifert-magnesium-test-kit\"\u003eSalifert Magnesium Test Kit\u003c\/a\u003e or \u003ca href=\"https:\/\/squeakysaquatics.com\/products\/hanna-hi783-marine-magnesium-checker-hc\"\u003eHanna Marine Magnesium Checker HC\u003c\/a\u003e. Browse the full \u003ca href=\"https:\/\/squeakysaquatics.com\/collections\/additives-supplements\"\u003eadditives \u0026amp; supplements collection\u003c\/a\u003e.\u003c\/p\u003e\n\n  \u003cdiv class=\"aq-callout\"\u003e\n    \u003cstrong\u003ePharmaceutical-grade. Made in the USA.\u003c\/strong\u003e Stable magnesium protects every dollar you spend on calcium and alkalinity dosing — without it, Ca and Alk will not hold.\n  \u003c\/div\u003e\n\n  \u003ch2\u003eWhy Magnesium Matters\u003c\/h2\u003e\n  \u003cp\u003eMagnesium acts as the buffer that keeps calcium and carbonate ions in solution. When Mg drops below ~1250 ppm, calcium and alkalinity become unstable and start to precipitate out as scale — turning your tank glass cloudy and starving corals of the minerals they need to grow. Most reef hobbyists target \u003cstrong\u003e1280–1380 ppm\u003c\/strong\u003e magnesium; salt mixes alone often fall short, especially in tanks with heavy SPS growth.\u003c\/p\u003e\n\n  \u003ch2\u003eFeatures — All Sizes\u003c\/h2\u003e\n  \u003cdiv class=\"aq-features\"\u003e\n    \u003cdiv class=\"aq-feature-card\"\u003e\n\u003cstrong\u003ePharmaceutical-Grade\u003c\/strong\u003e\u003cspan\u003eHigh-purity raw materials, no fillers.\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"aq-feature-card\"\u003e\n\u003cstrong\u003eReef-Safe Magnesium\u003c\/strong\u003e\u003cspan\u003eSafe for SPS, LPS, soft corals, anemones, and reef inverts.\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"aq-feature-card\"\u003e\n\u003cstrong\u003eStabilizes Ca \u0026amp; Alk\u003c\/strong\u003e\u003cspan\u003eKeeps calcium and alkalinity from precipitating.\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"aq-feature-card\"\u003e\n\u003cstrong\u003eLiquid — No Mixing\u003c\/strong\u003e\u003cspan\u003ePour straight from the bottle — no powders to dissolve.\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"aq-feature-card\"\u003e\n\u003cstrong\u003eMade in the USA\u003c\/strong\u003e\u003cspan\u003eManufactured by Fritz Aquatics in Mesquite, Texas.\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"aq-feature-card\"\u003e\n\u003cstrong\u003ePredictable Dosing\u003c\/strong\u003e\u003cspan\u003eDose to raise Mg slowly — no more than 100 ppm per day.\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"aq-feature-card\"\u003e\n\u003cstrong\u003eWorks With Dosers\u003c\/strong\u003e\u003cspan\u003eLiquid format is ideal for automatic dosing pumps.\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"aq-feature-card\"\u003e\n\u003cstrong\u003eRPM System Compatible\u003c\/strong\u003e\u003cspan\u003ePairs with Fritz RPM PT 1 (Alk) and PT 2 (Ca).\u003c\/span\u003e\n\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003ch2\u003eChoose Your Size — Variant Comparison\u003c\/h2\u003e\n  \u003cp class=\"aq-note\"\u003eSelect a size in the tab section below for the full individual spec sheet.\u003c\/p\u003e\n  \u003cdiv class=\"aq-compare\"\u003e\n    \u003ctable\u003e\n      \u003cthead\u003e\n        \u003ctr\u003e\n          \u003cth\u003eSpec\u003c\/th\u003e\n          \u003cth\u003e16 oz\u003c\/th\u003e\n          \u003cth\u003e32 oz\u003c\/th\u003e\n          \u003cth\u003e1 Gallon\u003c\/th\u003e\n          \u003cth\u003e5 Gallon\u003c\/th\u003e\n        \u003c\/tr\u003e\n      \u003c\/thead\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003ctd\u003eVolume\u003c\/td\u003e\n\u003ctd\u003e473 mL\u003c\/td\u003e\n\u003ctd\u003e946 mL\u003c\/td\u003e\n\u003ctd\u003e3.78 L\u003c\/td\u003e\n\u003ctd\u003e18.9 L\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003e80310\u003c\/td\u003e\n\u003ctd\u003e80311\u003c\/td\u003e\n\u003ctd\u003e80313\u003c\/td\u003e\n\u003ctd\u003e80314\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eForm Factor\u003c\/td\u003e\n\u003ctd\u003eRound bottle\u003c\/td\u003e\n\u003ctd\u003eRound bottle\u003c\/td\u003e\n\u003ctd\u003eJug w\/ handle\u003c\/td\u003e\n\u003ctd\u003eBucket w\/ handle\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eIdeal For\u003c\/td\u003e\n\u003ctd\u003eNano \/ pico reefs\u003c\/td\u003e\n\u003ctd\u003eSmall reefs 20–60 gal\u003c\/td\u003e\n\u003ctd\u003eMid reefs 60–180 gal\u003c\/td\u003e\n\u003ctd\u003eLarge \/ multi-tank systems\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eWorks With Dosers\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"aq-check\"\u003e✓\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"aq-check\"\u003e✓\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"aq-check\"\u003e✓\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"aq-check\"\u003e✓\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\n  \u003ch2\u003eDetailed Variant Specifications\u003c\/h2\u003e\n  \u003cp\u003eClick a size below to view its full specification sheet.\u003c\/p\u003e\n\n  \u003cinput type=\"radio\" class=\"aq-tab-radio\" id=\"aq-tab-16\" name=\"aq-spec-tab\" checked\u003e\n  \u003cinput type=\"radio\" class=\"aq-tab-radio\" id=\"aq-tab-32\" name=\"aq-spec-tab\"\u003e\n  \u003cinput type=\"radio\" class=\"aq-tab-radio\" id=\"aq-tab-1g\" name=\"aq-spec-tab\"\u003e\n  \u003cinput type=\"radio\" class=\"aq-tab-radio\" id=\"aq-tab-5g\" name=\"aq-spec-tab\"\u003e\n\n  \u003cdiv class=\"aq-tab-labels\"\u003e\n    \u003clabel for=\"aq-tab-16\" class=\"aq-tab-label\"\u003e16 oz — Nano\u003c\/label\u003e\n    \u003clabel for=\"aq-tab-32\" class=\"aq-tab-label\"\u003e32 oz — Small\u003c\/label\u003e\n    \u003clabel for=\"aq-tab-1g\" class=\"aq-tab-label\"\u003e1 Gallon — Mid\u003c\/label\u003e\n    \u003clabel for=\"aq-tab-5g\" class=\"aq-tab-label\"\u003e5 Gallon — Large\u003c\/label\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"aq-panels\"\u003e\n    \u003cdiv class=\"aq-tab-panel\" id=\"aq-panel-16\"\u003e\n      \u003ch3\u003e16 oz · Nano-Reef Bottle · SKU 80310\u003c\/h3\u003e\n      \u003cp\u003eThe 16 oz bottle is sized for nano and pico reef hobbyists running tanks up to about 20 gallons, or for anyone correcting a one-time low-Mg reading without committing to a larger jug.\u003c\/p\u003e\n      \u003ctable class=\"aq-specs-table\"\u003e\n        \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n        \u003ctbody\u003e\n          \u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003e80310\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eVolume\u003c\/td\u003e\n\u003ctd\u003e16 fl oz (473 mL)\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eBest for\u003c\/td\u003e\n\u003ctd\u003eNano \u0026amp; pico reefs (≤ 20 gal)\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eDispensing\u003c\/td\u003e\n\u003ctd\u003ePour cap, manual or doser\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eFritz Aquatics\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eMade In\u003c\/td\u003e\n\u003ctd\u003eUSA\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003c\/tbody\u003e\n      \u003c\/table\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"aq-tab-panel\" id=\"aq-panel-32\"\u003e\n      \u003ch3\u003e32 oz · Small-Reef Bottle · SKU 80311\u003c\/h3\u003e\n      \u003cp\u003eThe 32 oz bottle is the everyday size for small reefs in the 20–60 gallon range. Magnesium consumption tracks coral growth — this size lasts most casual hobbyists a few months.\u003c\/p\u003e\n      \u003ctable class=\"aq-specs-table\"\u003e\n        \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n        \u003ctbody\u003e\n          \u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003e80311\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eVolume\u003c\/td\u003e\n\u003ctd\u003e32 fl oz (946 mL)\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eBest for\u003c\/td\u003e\n\u003ctd\u003eSmall reefs (20–60 gal)\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eDispensing\u003c\/td\u003e\n\u003ctd\u003ePour cap, manual or doser\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eFritz Aquatics\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eMade In\u003c\/td\u003e\n\u003ctd\u003eUSA\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003c\/tbody\u003e\n      \u003c\/table\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"aq-tab-panel\" id=\"aq-panel-1g\"\u003e\n      \u003ch3\u003e1 Gallon · Mid-Reef Jug · SKU 80313\u003c\/h3\u003e\n      \u003cp\u003eThe 1 Gallon jug is the sweet spot for the typical mid-sized reef tank (60–180 gallons). Best value per ounce for hobbyists running a dedicated Mg dosing channel.\u003c\/p\u003e\n      \u003ctable class=\"aq-specs-table\"\u003e\n        \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n        \u003ctbody\u003e\n          \u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003e80313\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eVolume\u003c\/td\u003e\n\u003ctd\u003e1 US Gallon (3.78 L)\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eBest for\u003c\/td\u003e\n\u003ctd\u003eMid reefs (60–180 gal)\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eDispensing\u003c\/td\u003e\n\u003ctd\u003eCarry handle, gravity-feed or doser pickup\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eFritz Aquatics\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eMade In\u003c\/td\u003e\n\u003ctd\u003eUSA\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003c\/tbody\u003e\n      \u003c\/table\u003e\n    \u003c\/div\u003e\n\n    \u003cdiv class=\"aq-tab-panel\" id=\"aq-panel-5g\"\u003e\n      \u003ch3\u003e5 Gallon · Large-System Bucket · SKU 80314\u003c\/h3\u003e\n      \u003cp\u003eThe 5 Gallon bucket is built for large reefs and frag systems. Long runway between refills for hobbyists with high Mg consumption from heavy SPS growth.\u003c\/p\u003e\n      \u003ctable class=\"aq-specs-table\"\u003e\n        \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n        \u003ctbody\u003e\n          \u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003e80314\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eVolume\u003c\/td\u003e\n\u003ctd\u003e5 US Gallons (18.9 L)\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eBest for\u003c\/td\u003e\n\u003ctd\u003eLarge reefs, frag tanks, multi-tank rooms\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eDispensing\u003c\/td\u003e\n\u003ctd\u003eSealed bucket w\/ handle, dosing tube pickup\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eFritz Aquatics\u003c\/td\u003e\n\u003c\/tr\u003e\n          \u003ctr\u003e\n\u003ctd\u003eMade In\u003c\/td\u003e\n\u003ctd\u003eUSA\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003c\/tbody\u003e\n      \u003c\/table\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003ch2\u003eWhich Size Is Right for You?\u003c\/h2\u003e\n  \u003cp\u003e\u003cstrong\u003e16 oz\u003c\/strong\u003e — Best for pico\/nano reefs (≤ 20 gal) or correcting a single low reading.\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003e32 oz\u003c\/strong\u003e — The everyday size for small reefs in the 20–60 gallon range.\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003e1 Gallon\u003c\/strong\u003e — Best value for mid-reef hobbyists running ongoing Mg supplementation.\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003e5 Gallon\u003c\/strong\u003e — The choice for large reefs and SPS-dominant systems with high Mg consumption.\u003c\/p\u003e\n\n  \u003ch2\u003eHow to Dose\u003c\/h2\u003e\n  \u003cp\u003eTest your magnesium first. If your Mg is below 1280 ppm, dose \u003cstrong\u003eno more than 100 ppm of correction per day\u003c\/strong\u003e to avoid stressing livestock. Spread the dose throughout the day, ideally in a high-flow area of the sump or display. Retest 24 hours after dosing before applying another correction. For ongoing maintenance, dose daily based on your tank's measured Mg consumption rate.\u003c\/p\u003e\n\n  \u003ch2\u003eFAQ\u003c\/h2\u003e\n  \u003cp\u003e\u003cstrong\u003eWhat Mg level should I target?\u003c\/strong\u003e\u003cbr\u003eMost reef tanks do well at \u003cstrong\u003e1280–1380 ppm\u003c\/strong\u003e. SPS-dominant tanks often run slightly higher (1350–1400) for stability margin.\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003eWhy does my Mg keep dropping?\u003c\/strong\u003e\u003cbr\u003eHeavy coral growth, calcium reactor use, frequent dosing of Ca and Alk, and even some salt mixes can pull Mg down over time. Test weekly and dose to maintain.\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003eCan I dose PT 3 at the same time as PT 1 and PT 2?\u003c\/strong\u003e\u003cbr\u003eYes — unlike Ca and Alk, magnesium can be dosed alongside either without precipitation issues. Many hobbyists dose Mg first, then Alk, then Ca on separate dosing pumps.\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003eIs it safe for refugiums, inverts, and macroalgae?\u003c\/strong\u003e\u003cbr\u003eYes. Mg supplementation at the recommended rate is reef-safe and supports invertebrate shell\/skeleton health.\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003eDo I still need this if I do regular water changes?\u003c\/strong\u003e\u003cbr\u003eFor lightly stocked tanks with frequent large water changes, water changes alone can keep Mg in range. Most tanks with significant coral growth need supplementation between changes.\u003c\/p\u003e\n\n\u003c\/div\u003e","brand":"Fritz","offers":[{"title":"16 oz","offer_id":48742070485211,"sku":"80310","price":10.39,"currency_code":"USD","in_stock":true},{"title":"32 oz","offer_id":48742070517979,"sku":"80311","price":14.39,"currency_code":"USD","in_stock":true},{"title":"1 Gallon","offer_id":48742070550747,"sku":"80313","price":31.19,"currency_code":"USD","in_stock":false},{"title":"5 Gallon","offer_id":48742070583515,"sku":"80314","price":79.19,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0767\/5209\/3403\/files\/image_18980d62-eea2-470c-8b7a-73b97ed549d5.png?v=1777898832","url":"https:\/\/squeakysaquatics.com\/products\/fritz-rpm-liquid-pt-3-magnesium-reef-supplement","provider":"Squeaky's Aquatics","version":"1.0","type":"link"}