{"product_id":"fritz-rpm-liquid-pt-2-calcium-reef-supplement","title":"Fritz RPM Liquid PT 2 Calcium | 2-Part Calcium Supplement for Reef Aquariums","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 2 Calcium\u003c\/strong\u003e is part two of the Fritz \u003cem\u003eReef Pro Mineral\u003c\/em\u003e two-part dosing system, formulated to replenish the calcium (Ca) consumed by SPS, LPS, and soft corals as they build their carbonate skeletons. Pharmaceutical-grade and made in the USA, RPM PT 2 keeps your reef chemistry rock-solid between water changes.\u003c\/p\u003e\n\n  \u003cp\u003ePair PT 2 with \u003cstrong\u003eFritz RPM PT 1 (Alkalinity)\u003c\/strong\u003e for full two-part dosing, and verify levels with a precision \u003ca href=\"https:\/\/squeakysaquatics.com\/products\/salifert-calcium-test-kit\"\u003eSalifert Calcium Test Kit\u003c\/a\u003e or \u003ca href=\"https:\/\/squeakysaquatics.com\/products\/hanna-hi758-marine-calcium-colorimeter\"\u003eHanna Marine Calcium Checker HC\u003c\/a\u003e. Browse the full \u003ca href=\"https:\/\/squeakysaquatics.com\/collections\/additives-supplements\"\u003eadditives \u0026amp; supplements collection\u003c\/a\u003e for the rest of your reef chemistry lineup.\u003c\/p\u003e\n\n  \u003cdiv class=\"aq-callout\"\u003e\n    \u003cstrong\u003ePharmaceutical-grade. Made in the USA.\u003c\/strong\u003e Every Fritz RPM bottle is blended from high-purity raw materials and quality-tested. No fillers, no surprises — just clean, predictable calcium dosing.\n  \u003c\/div\u003e\n\n  \u003ch2\u003eHow It Works\u003c\/h2\u003e\n  \u003cp\u003eCorals consume calcium and alkalinity in roughly equal proportion as they grow their calcium-carbonate skeletons. As Ca drops, coral growth stalls and skeletons can stop forming. RPM PT 2 delivers a balanced liquid calcium supplement that you dose daily — alongside RPM PT 1 (alkalinity) — to keep calcium steady in the reef-safe range of \u003cstrong\u003e400–450 ppm\u003c\/strong\u003e.\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 industrial fillers.\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"aq-feature-card\"\u003e\n\u003cstrong\u003eTwo-Part Balanced\u003c\/strong\u003e\u003cspan\u003eDesigned to dose alongside RPM PT 1 (Alkalinity) in equal volumes.\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003cdiv class=\"aq-feature-card\"\u003e\n\u003cstrong\u003eReef-Safe Formula\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\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 in equal volume to PT 1 for balanced reef chemistry.\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\u003eStable Shelf Life\u003c\/strong\u003e\u003cspan\u003eSealed bottles store well in a cool, dark cabinet.\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\u003e80305\u003c\/td\u003e\n\u003ctd\u003e80306\u003c\/td\u003e\n\u003ctd\u003e80308\u003c\/td\u003e\n\u003ctd\u003e80309\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 80305\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 trialling RPM dosing before 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\u003e80305\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 80306\u003c\/h3\u003e\n      \u003cp\u003eThe 32 oz bottle is the everyday size for small reefs in the 20–60 gallon range. About double the dosing runway of the 16 oz with the same convenient bottle format.\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\u003e80306\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 80308\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 daily two-part doses with a peristaltic doser.\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\u003e80308\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 80309\u003c\/h3\u003e\n      \u003cp\u003eThe 5 Gallon bucket is built for large reefs, frag systems, and multi-tank fishrooms. Months of dosing runway in one container; pulls comfortably with a stiff dosing tube and weighted strainer.\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\u003e80309\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 — Pick this for pico\/nano reefs (≤ 20 gal), or to trial RPM dosing before stepping up.\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 the typical mid-reef hobbyist running daily two-part doses on a 60–180 gallon system.\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003e5 Gallon\u003c\/strong\u003e — The choice for large reefs, frag systems, and anyone running multiple tanks who wants months of runway.\u003c\/p\u003e\n\n  \u003ch2\u003eHow to Dose\u003c\/h2\u003e\n  \u003cp\u003eTest your current calcium to establish a baseline. As a starting point, dose \u003cstrong\u003e1 mL of RPM PT 2 per gallon of tank water\u003c\/strong\u003e to raise calcium approximately \u003cstrong\u003e2.5 ppm\u003c\/strong\u003e — then adjust based on your daily consumption rate after running a 48-hour test sequence. Always dose PT 1 and PT 2 separately (different times of day, or different points in the sump) to avoid precipitation. Never combine them in the same dosing reservoir.\u003c\/p\u003e\n\n  \u003ch2\u003eFAQ\u003c\/h2\u003e\n  \u003cp\u003e\u003cstrong\u003eDo I need to dose PT 1 (Alkalinity) at the same time?\u003c\/strong\u003e\u003cbr\u003eYes — RPM is a two-part system. Calcium and alkalinity are consumed together by coral skeletal growth, so dose roughly equal volumes of PT 1 and PT 2 daily, spaced apart by at least an hour to prevent precipitation.\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003eWhat calcium level should I target?\u003c\/strong\u003e\u003cbr\u003eMost reef hobbyists target \u003cstrong\u003e400–450 ppm calcium\u003c\/strong\u003e. SPS-dominant tanks often run on the higher end and prioritize stability over absolute number.\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003eWill PT 2 affect pH or alkalinity?\u003c\/strong\u003e\u003cbr\u003ePT 2 is calcium chloride based and is pH-neutral. It does not directly affect alkalinity, which is why PT 1 must be dosed alongside.\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003eCan I use this in a fish-only saltwater tank?\u003c\/strong\u003e\u003cbr\u003eYou can, but there's no need — fish-only systems don't consume calcium quickly. Weekly water changes with a quality reef salt cover everything a FOWLR tank needs.\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003eIs it safe for refugiums, sumps, and inverts?\u003c\/strong\u003e\u003cbr\u003eYes. RPM PT 2 is reef-safe when dosed at the recommended rate and is compatible with shrimp, snails, starfish, anemones, and macroalgae refugiums.\u003c\/p\u003e\n\n\u003c\/div\u003e","brand":"Fritz","offers":[{"title":"16 oz","offer_id":48742013370587,"sku":"80305","price":9.59,"currency_code":"USD","in_stock":true},{"title":"32 oz","offer_id":48742013403355,"sku":"80306","price":11.99,"currency_code":"USD","in_stock":true},{"title":"1 Gallon","offer_id":48742013436123,"sku":"80308","price":23.99,"currency_code":"USD","in_stock":false},{"title":"5 Gallon","offer_id":48742013468891,"sku":"80309","price":65.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0767\/5209\/3403\/files\/image_dda11b99-9c77-4645-9668-ae1c2e546bfb.png?v=1777898637","url":"https:\/\/squeakysaquatics.com\/products\/fritz-rpm-liquid-pt-2-calcium-reef-supplement","provider":"Squeaky's Aquatics","version":"1.0","type":"link"}