{"title":"Black Friday 2026 | Reef Endurance — 30% Off | Nov 20–30","description":"\u003cp\u003e\u003cstrong\u003eUpcoming sale: November 20–30, 2026 (Central Time).\u003c\/strong\u003e Save 30% on selected Reef Endurance bulk dosing additives, aquarium carbon, GFO and calcium reactor media during these dates.\u003c\/p\u003e\u003cp\u003eThe discount will apply automatically to eligible one-time purchases in your cart or at checkout during the stated sale dates.\u003c\/p\u003e\u003cp\u003eOnly the products shown in this collection are included in this offer; other products are excluded. Please check individual product pages for availability and fulfillment details.\u003c\/p\u003e","products":[{"product_id":"reef-endurance-bulk-calcium-chloride-2-5lbs-re-cachl-b","title":"Reef Endurance Bulk Calcium Chloride 2.5lbs","description":"\u003cp\u003eReef Endurance Bulk Calcium Chloride 2.5lbs is a pharmaceutical-grade calcium chloride dihydrate powder for restoring and maintaining calcium levels in reef aquariums, sized as a resealable 2.5 lb bag for smaller systems or as a top-off refill.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 2.5 lbs (1.13 kg), resealable bag\u003c\/li\u003e\n\u003cli\u003eMix ratio: 100g calcium chloride per 1L RO\/DI water\u003c\/li\u003e\n\u003cli\u003eYields approximately 3 gallons of concentrated stock solution when fully mixed\u003c\/li\u003e\n\u003cli\u003eDosing: 1 mL of stock solution raises calcium ~10 ppm per 1 US gallon of tank water\u003c\/li\u003e\n\u003cli\u003eTarget reef calcium range: 412-450 ppm\u003c\/li\u003e\n\u003cli\u003eMaximum recommended daily increase: 50 ppm\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: stony corals and coralline algae pull calcium out of reef water constantly as they build skeleton, so most reef tanks need daily or near-daily dosing. This pharmaceutical-based formula dissolves crystal clear with no visible residue, so routine two-part dosing won't cloud the water or introduce the impurities found in lower-grade calcium chloride.\u003c\/p\u003e\u003cp\u003eIncludes: 2.5 lb resealable bag of calcium chloride dihydrate powder. Pair with a sodium bicarbonate or soda ash alkalinity buffer for a complete two-part dosing system.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598024236,"sku":"RE-CACHL-B","price":15.74,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/re_calciumchloride_front.jpg?v=1787190524"},{"product_id":"reef-endurance-bulk-calcium-chloride-30lbs-re-cachl-xl","title":"Reef Endurance Bulk Calcium Chloride 30lbs","description":"\u003cp\u003eReef Endurance Bulk Calcium Chloride 30lbs is a pharmaceutical-grade calcium chloride dihydrate powder packed in a resealable 5-gallon bucket, sized for high-volume reef systems and multi-tank fish rooms that need calcium chloride stock solution in bulk.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 30 lbs (13.6 kg) in a resealable 5-gallon bucket\u003c\/li\u003e\n\u003cli\u003eMix ratio: 100g calcium chloride per 1L RO\/DI water\u003c\/li\u003e\n\u003cli\u003eYields approximately 36 gallons of concentrated stock solution when fully mixed\u003c\/li\u003e\n\u003cli\u003eDosing: 1 mL of stock solution raises calcium ~10 ppm per 1 US gallon of tank water\u003c\/li\u003e\n\u003cli\u003eTarget reef calcium range: 412-450 ppm\u003c\/li\u003e\n\u003cli\u003eMaximum recommended daily increase: 50 ppm\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: large reef systems and multi-tank operations burn through calcium chloride fast, and buying in a 30 lb bucket instead of repeated small bags cuts the cost per gallon of stock solution significantly while keeping the same crystal-clear, low-residue pharmaceutical-grade formula. Mix a fresh batch as needed rather than storing large volumes of premixed solution.\u003c\/p\u003e\u003cp\u003eIncludes: 30 lb (5-gallon bucket) of calcium chloride dihydrate powder. Pair with Reef Endurance sodium bicarbonate or soda ash for a complete two-part dosing system.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598057004,"sku":"RE-CACHL-XL","price":157.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/reef_endurance_calcium_chloride_30lbs.jpg?v=1787190524"},{"product_id":"reef-endurance-aquarium-carbon-1-gallon-re-carb-lg","title":"Reef Endurance Aquarium Carbon 1 gallon","description":"\u003cp\u003eReef Endurance Aquarium Carbon 1 gallon is a virgin coal-based granular activated carbon (GAC) for removing discoloration, odors, and dissolved organics from freshwater and marine aquariums.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eContainer size: 1 gallon of granular carbon\u003c\/li\u003e\n\u003cli\u003eSource: virgin coal-based GAC with high surface area and low-dust granules\u003c\/li\u003e\n\u003cli\u003eDosage: 1 tablespoon per 8 gallons of tank water\u003c\/li\u003e\n\u003cli\u003eOne container holds enough carbon for a full dose in aquariums up to approximately 2,048 gallons combined\u003c\/li\u003e\n\u003cli\u003eUse in a canister filter, media reactor, or mesh bag placed in a moderate-flow area of the sump\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: dissolved organics and yellowing compounds build up in reef and freshwater systems between water changes, dulling water clarity and re-releasing nitrogenous waste back into the tank. A high-surface-area, low-dust GAC like this pulls those compounds out efficiently without clouding the water on first use, which matters most in display tanks where a milky carbon dose right after a fresh charge is the last thing you want.\u003c\/p\u003e\u003cp\u003eIncludes: 1 gallon of virgin coal-based granular activated carbon. Rinse thoroughly before use.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598089772,"sku":"RE-CARB-LG","price":37.79,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/carbonmedia2.jpg?v=1787190524"},{"product_id":"reef-endurance-aquarium-carbon-1-2-gallon-re-carb-md","title":"Reef Endurance Aquarium Carbon 1\/2 gallon","description":"\u003cp\u003eReef Endurance Aquarium Carbon 1\/2 gallon is a virgin coal-based granular activated carbon (GAC) for removing discoloration, odors, and dissolved organics from freshwater and marine aquariums.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eContainer size: 1\/2 gallon of granular carbon\u003c\/li\u003e\n\u003cli\u003eSource: virgin coal-based GAC with high surface area and low-dust granules\u003c\/li\u003e\n\u003cli\u003eDosage: 1 tablespoon per 8 gallons of tank water\u003c\/li\u003e\n\u003cli\u003eOne container holds enough carbon for a full dose in aquariums up to approximately 1,024 gallons combined\u003c\/li\u003e\n\u003cli\u003eUse in a canister filter, media reactor, or mesh bag placed in a moderate-flow area of the sump\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: dissolved organics and yellowing compounds build up in reef and freshwater systems between water changes, dulling water clarity and re-releasing nitrogenous waste back into the tank. A high-surface-area, low-dust GAC like this pulls those compounds out efficiently without clouding the water on first use, which matters most in display tanks where a milky carbon dose right after a fresh charge is the last thing you want.\u003c\/p\u003e\u003cp\u003eIncludes: 1\/2 gallon of virgin coal-based granular activated carbon. Rinse thoroughly before use.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598122540,"sku":"RE-CARB-MD","price":30.44,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/carbonmedia2_2d4e5b82-a09e-458d-8595-970b96ccdc40.jpg?v=1787190525"},{"product_id":"reef-endurance-aquarium-carbon-1-4-gallon-re-carb-sm","title":"Reef Endurance Aquarium Carbon 1\/4 gallon","description":"\u003cp\u003eReef Endurance Aquarium Carbon 1\/4 gallon is a virgin coal-based granular activated carbon (GAC) for removing discoloration, odors, and dissolved organics from freshwater and marine aquariums.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eContainer size: 1\/4 gallon of granular carbon\u003c\/li\u003e\n\u003cli\u003eSource: virgin coal-based GAC with high surface area and low-dust granules\u003c\/li\u003e\n\u003cli\u003eDosage: 1 tablespoon per 8 gallons of tank water\u003c\/li\u003e\n\u003cli\u003eOne container holds enough carbon for a full dose in aquariums up to approximately 512 gallons combined\u003c\/li\u003e\n\u003cli\u003eUse in a canister filter, media reactor, or mesh bag placed in a moderate-flow area of the sump\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: dissolved organics and yellowing compounds build up in reef and freshwater systems between water changes, dulling water clarity and re-releasing nitrogenous waste back into the tank. A high-surface-area, low-dust GAC like this pulls those compounds out efficiently without clouding the water on first use — a good fit for nano and mid-size tanks that only need a small charge replaced every few weeks rather than a large bulk container.\u003c\/p\u003e\u003cp\u003eIncludes: 1\/4 gallon of virgin coal-based granular activated carbon. Rinse thoroughly before use.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598155308,"sku":"RE-CARB-SM","price":15.74,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/carbonmedia2_a3f14990-f3e8-45ce-91f2-375b8c553986.jpg?v=1787190525"},{"product_id":"reef-endurance-aquarium-carbon-5-gallon-re-carb-xl","title":"Reef Endurance Aquarium Carbon 5 gallon","description":"\u003cp\u003eReef Endurance Aquarium Carbon 5 gallon is a virgin coal-based granular activated carbon (GAC) for removing discoloration, odors, and dissolved organics from freshwater and marine aquariums, packed in bulk for large systems and multi-tank fish rooms.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eContainer size: 5 gallon bucket of granular carbon\u003c\/li\u003e\n\u003cli\u003eSource: virgin coal-based GAC with high surface area and low-dust granules\u003c\/li\u003e\n\u003cli\u003eDosage: 1 tablespoon per 8 gallons of tank water\u003c\/li\u003e\n\u003cli\u003eOne bucket holds enough carbon for a full dose in aquariums up to approximately 10,240 gallons combined\u003c\/li\u003e\n\u003cli\u003eUse in a canister filter, media reactor, or mesh bag placed in a moderate-flow area of the sump\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: dissolved organics and yellowing compounds build up in reef and freshwater systems between water changes, dulling water clarity and re-releasing nitrogenous waste back into the tank. A high-surface-area, low-dust GAC like this pulls those compounds out efficiently without clouding the water on first use. Buying a 5 gallon bucket instead of repeated small containers cuts the cost per dose for stores, frag farms, and multi-tank fish rooms cycling carbon regularly.\u003c\/p\u003e\u003cp\u003eIncludes: 5 gallon bucket of virgin coal-based granular activated carbon. Rinse thoroughly before use.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598188076,"sku":"RE-CARB-XL","price":136.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/carbonmedia2_2adf7054-a27e-4aea-ad29-326f827d9364.jpg?v=1787190526"},{"product_id":"reef-endurance-large-calcium-media-case-of-4-re-crm-x5lg","title":"Reef Endurance Large Calcium Media case of 4","description":"\u003cp\u003eReef Endurance Large Calcium Media (case of 4) is coarse-grain aragonite reactor media for calcium reactors running larger reef systems, supplying calcium, carbonate alkalinity, and trace elements as it dissolves.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eGrain size: 4-6mm average (large granule)\u003c\/li\u003e\n\u003cli\u003eSource: natural aragonite rubble from sustainably harvested fossil corals\u003c\/li\u003e\n\u003cli\u003ePackaging: four 4kg bags per case, 16kg (35.2 lbs) total\u003c\/li\u003e\n\u003cli\u003eDissolves effectively at a reactor effluent pH around 6.7-6.8\u003c\/li\u003e\n\u003cli\u003eRinse with RO\/DI water before loading into the reactor\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: large 4-6mm rubble resists compacting and channeling inside a calcium reactor's media chamber far better than fine sand, so CO2-charged water keeps flowing evenly through the whole bed instead of carving a single path through it — that even flow is what keeps calcium and alkalinity output stable over time and prevents dead zones that stop dissolving media.\u003c\/p\u003e\u003cp\u003eIncludes: four 4kg (8.8 lb) resealable bags of large-granule aragonite reactor media, 16kg (35.2 lbs) total. Sold as the sole media fill for calcium reactors.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598220844,"sku":"RE-CRM-X5LG","price":94.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/re_largemedia4kgbag_1.jpg?v=1787190526"},{"product_id":"reef-endurance-small-calcium-media-case-of-4-re-crm-x5sm","title":"Reef Endurance Small Calcium Media case of 4","description":"\u003cp\u003eReef Endurance Small Calcium Media (case of 4) is fine-grain aragonite reactor media sized for small calcium reactors or as a secondary post-reactor buffering chamber, supplying calcium, carbonate alkalinity, and trace elements as it dissolves.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eGrain size: 3-4mm average (small granule)\u003c\/li\u003e\n\u003cli\u003eSource: natural aragonite rubble from sustainably harvested fossil corals\u003c\/li\u003e\n\u003cli\u003ePackaging: four 4kg bags per case, 16kg (35.2 lbs) total\u003c\/li\u003e\n\u003cli\u003eDissolves effectively at a reactor effluent pH around 6.7-6.8\u003c\/li\u003e\n\u003cli\u003eRinse with RO\/DI water before loading into the reactor\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: smaller 3-4mm rubble packs more dissolving surface area into a compact reactor chamber than large granules, which is exactly what a small reactor or a second-stage pH buffering chamber needs — more contact between the CO2-charged water and the media in a limited space means more consistent calcium and alkalinity output per pass.\u003c\/p\u003e\u003cp\u003eIncludes: four 4kg (8.8 lb) resealable bags of small-granule aragonite reactor media, 16kg (35.2 lbs) total. Sold as the sole media fill for calcium reactors.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598286380,"sku":"RE-CRM-X5SM","price":94.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/re_smallmedia4kgbag_1.jpg?v=1787190582"},{"product_id":"reef-endurance-gfo-4-5lbs-re-gfo-lg","title":"Reef Endurance GFO 4.5lbs","description":"\u003cp\u003eReef Endurance GFO 4.5lbs is a granular ferric oxide (GFO) phosphate-removal media for freshwater and marine aquariums, sized as a large bag for bigger reef systems or less frequent media changes.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 4.5 lbs of granular ferric oxide\u003c\/li\u003e\n\u003cli\u003eBinds: phosphate, silicate, and arsenic via a porous, high-surface-area structure\u003c\/li\u003e\n\u003cli\u003eReactor flow rate: approximately 100 gph (400 L\/hr) with gentle tumbling motion\u003c\/li\u003e\n\u003cli\u003eDosing: initial dose 1 tablespoon per 10 gallons; maintenance dose 2 tablespoons per 10 gallons\u003c\/li\u003e\n\u003cli\u003eReplace every 4-6 weeks, or sooner if phosphate levels start rising\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: elevated phosphate and silicate feed nuisance algae and dull coral color, so a media that adsorbs both keeps a reef display cleaner between water changes. GFO ties up phosphorus through iron-oxide chemistry rather than bacterial competition, so it keeps working in tanks where a refugium or carbon dosing isn't practical. Rinse thoroughly until the water runs clear before adding to a reactor or filter bag — GFO fines will cloud the water if added straight from the bag.\u003c\/p\u003e\u003cp\u003eIncludes: 4.5 lb bag of granular ferric oxide phosphate-removal media. Works in an upflow media reactor or passively in a mesh filter bag.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598319148,"sku":"RE-GFO-LG","price":125.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/reefendurance_gfo_pg.jpg?v=1787190583"},{"product_id":"reef-endurance-gfo-2-5lbs-re-gfo-md","title":"Reef Endurance GFO 2.5lbs","description":"\u003cp\u003eReef Endurance GFO 2.5lbs is a granular ferric oxide (GFO) phosphate-removal media for freshwater and marine aquariums, sized as a medium bag for standard reef and mixed-fish tanks.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 2.5 lbs of granular ferric oxide\u003c\/li\u003e\n\u003cli\u003eBinds: phosphate, silicate, and arsenic via a porous, high-surface-area structure\u003c\/li\u003e\n\u003cli\u003eReactor flow rate: approximately 100 gph (400 L\/hr) with gentle tumbling motion\u003c\/li\u003e\n\u003cli\u003eDosing: initial dose 1 tablespoon per 10 gallons; maintenance dose 2 tablespoons per 10 gallons\u003c\/li\u003e\n\u003cli\u003eReplace every 4-6 weeks, or sooner if phosphate levels start rising\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: elevated phosphate and silicate feed nuisance algae and dull coral color, so a media that adsorbs both keeps a reef display cleaner between water changes. GFO ties up phosphorus through iron-oxide chemistry rather than bacterial competition, so it keeps working in tanks where a refugium or carbon dosing isn't practical. Rinse thoroughly until the water runs clear before adding to a reactor or filter bag — GFO fines will cloud the water if added straight from the bag.\u003c\/p\u003e\u003cp\u003eIncludes: 2.5 lb bag of granular ferric oxide phosphate-removal media. Works in an upflow media reactor or passively in a mesh filter bag.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598351916,"sku":"RE-GFO-MD","price":73.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/reefendurance_gfo_pg_bb3d8d5d-5d99-4a0a-abd9-b05e38f19f85.jpg?v=1787190583"},{"product_id":"reef-endurance-gfo-1-25lbs-re-gfo-sm","title":"Reef Endurance GFO 1.25lbs","description":"\u003cp\u003eReef Endurance GFO 1.25lbs is a granular ferric oxide (GFO) phosphate-removal media for freshwater and marine aquariums, sized as a small bag for nano to mid-size tanks or as a top-off refill.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 1.25 lbs of granular ferric oxide\u003c\/li\u003e\n\u003cli\u003eBinds: phosphate, silicate, and arsenic via a porous, high-surface-area structure\u003c\/li\u003e\n\u003cli\u003eReactor flow rate: approximately 100 gph (400 L\/hr) with gentle tumbling motion\u003c\/li\u003e\n\u003cli\u003eDosing: initial dose 1 tablespoon per 10 gallons; maintenance dose 2 tablespoons per 10 gallons\u003c\/li\u003e\n\u003cli\u003eReplace every 4-6 weeks, or sooner if phosphate levels start rising\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: elevated phosphate and silicate feed nuisance algae and dull coral color, so a media that adsorbs both keeps a reef display cleaner between water changes. GFO ties up phosphorus through iron-oxide chemistry rather than bacterial competition, so it keeps working in tanks where a refugium or carbon dosing isn't practical. Rinse thoroughly until the water runs clear before adding to a reactor or filter bag — GFO fines will cloud the water if added straight from the bag.\u003c\/p\u003e\u003cp\u003eIncludes: 1.25 lb bag of granular ferric oxide phosphate-removal media. Works in an upflow media reactor or passively in a mesh filter bag.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598384684,"sku":"RE-GFO-SM","price":41.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/reefendurance_gfo_pg_34896984-1445-4cf2-b1ce-d7702d96b4f5.jpg?v=1787190583"},{"product_id":"reef-endurance-gfo-24lbs-re-gfo-xl","title":"Reef Endurance GFO 24lbs","description":"\u003cp\u003eReef Endurance GFO 24lbs is a bulk granular ferric oxide (GFO) phosphate-removal media for large reef systems, multi-tank fish rooms, and stores running several reactors at once.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 24 lbs of granular ferric oxide, bulk packaging\u003c\/li\u003e\n\u003cli\u003eBinds: phosphate, silicate, and arsenic via a porous, high-surface-area structure\u003c\/li\u003e\n\u003cli\u003eReactor flow rate: approximately 100 gph (400 L\/hr) with gentle tumbling motion\u003c\/li\u003e\n\u003cli\u003eDosing: initial dose 1 tablespoon per 10 gallons; maintenance dose 2 tablespoons per 10 gallons\u003c\/li\u003e\n\u003cli\u003eReplace every 4-6 weeks, or sooner if phosphate levels start rising\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: elevated phosphate and silicate feed nuisance algae and dull coral color, so a media that adsorbs both keeps a reef display cleaner between water changes. Buying a 24 lb bulk bag instead of repeated small bags cuts the cost per media change significantly for anyone running reactors on more than one system. Rinse thoroughly until the water runs clear before adding to a reactor or filter bag — GFO fines will cloud the water if added straight from the bag.\u003c\/p\u003e\u003cp\u003eIncludes: 24 lb bulk bag of granular ferric oxide phosphate-removal media. Works in an upflow media reactor or passively in a mesh filter bag.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598417452,"sku":"RE-GFO-XL","price":556.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/reefendurance_gfo_pg_f9c00e3e-9ca2-444a-a2a0-9716a8483813.jpg?v=1787190584"},{"product_id":"reef-endurance-bulk-sodium-bicarbonate-4-5lbs-re-khbfr-b","title":"Reef Endurance Bulk Sodium Bicarbonate 4.5lbs","description":"\u003cp\u003eReef Endurance Bulk Sodium Bicarbonate 4.5lbs is a pharmaceutical-grade sodium bicarbonate powder for buffering and maintaining alkalinity in reef aquariums, packed as a resealable 4.5 lb bag.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 4.5 lbs, resealable bag\u003c\/li\u003e\n\u003cli\u003eMix ratio: 297g (about 1 1\/8 cups) sodium bicarbonate per 1 gallon RO\/DI water\u003c\/li\u003e\n\u003cli\u003eYields approximately 6.9 gallons of concentrated stock solution when fully mixed\u003c\/li\u003e\n\u003cli\u003eDosing: 63.7 mL of stock solution raises alkalinity approximately 1 dKH in a 45-gallon aquarium\u003c\/li\u003e\n\u003cli\u003eTarget reef alkalinity range: 8.0-12.0 dKH\u003c\/li\u003e\n\u003cli\u003eMaximum recommended daily increase: 1 dKH\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: sodium bicarbonate raises alkalinity with a mild, self-limiting pH effect — it nudges pH slightly downward rather than up — which makes it the safer buffer choice for reef tanks that already run on the high side of the pH range. (Soda ash is the better pick for tanks with naturally low pH.) Pair it with Reef Endurance Calcium Chloride for a complete two-part dosing system.\u003c\/p\u003e\u003cp\u003eIncludes: 4.5 lb resealable bag of sodium bicarbonate powder.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598450220,"sku":"RE-KHBFR-B","price":18.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/re_sodiumbicarbonate_front.jpg?v=1787190584"},{"product_id":"reef-endurance-bulk-sodium-bicarbonate-30lbs-re-khbfr-xl","title":"Reef Endurance Bulk Sodium Bicarbonate 30lbs","description":"\u003cp\u003eReef Endurance Bulk Sodium Bicarbonate 30lbs is a pharmaceutical-grade sodium bicarbonate powder packed in a resealable 5-gallon bucket, sized for high-volume reef systems and multi-tank fish rooms that need alkalinity buffer stock solution in bulk.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 30 lbs (13.6 kg) in a resealable 5-gallon bucket\u003c\/li\u003e\n\u003cli\u003eMix ratio: 297g (about 1 1\/8 cups) sodium bicarbonate per 1 gallon RO\/DI water\u003c\/li\u003e\n\u003cli\u003eYields approximately 46 gallons of concentrated stock solution when fully mixed\u003c\/li\u003e\n\u003cli\u003eDosing: 63.7 mL of stock solution raises alkalinity approximately 1 dKH in a 45-gallon aquarium\u003c\/li\u003e\n\u003cli\u003eTarget reef alkalinity range: 8.0-12.0 dKH\u003c\/li\u003e\n\u003cli\u003eMaximum recommended daily increase: 1 dKH\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: sodium bicarbonate raises alkalinity with a mild, self-limiting pH effect — it nudges pH slightly downward rather than up — making it the safer buffer choice for reef tanks that already run on the high side of the pH range. Large systems and multi-tank operations burn through kH buffer fast, and a 30 lb bucket cuts the cost per gallon of stock solution versus repeated small bags. Pair it with Reef Endurance Calcium Chloride for a complete two-part dosing system.\u003c\/p\u003e\u003cp\u003eIncludes: 30 lb (5-gallon bucket) of sodium bicarbonate powder.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598482988,"sku":"RE-KHBFR-XL","price":157.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/reef_endurance_sodium_bicarbonate_30ibs.jpg?v=1787190585"},{"product_id":"reef-endurance-bulk-magnesium-chloride-3lbs-re-mgchl-b","title":"Reef Endurance Bulk Magnesium Chloride 3lbs","description":"\u003cp\u003eReef Endurance Bulk Magnesium Chloride 3lbs is a pharmaceutical-grade magnesium chloride powder for maintaining magnesium levels in reef aquariums, used together with Reef Endurance Magnesium Sulfate to build a complete stock solution.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 3 lbs, resealable bag\u003c\/li\u003e\n\u003cli\u003eMix ratio (per 1 gallon RO\/DI water): 1181.25g magnesium chloride + 378g magnesium sulfate\u003c\/li\u003e\n\u003cli\u003eYields approximately 1.15 gallons of concentrated stock solution when paired with the matching magnesium sulfate\u003c\/li\u003e\n\u003cli\u003eDosing: 1 mL of stock solution raises magnesium approximately 14 ppm per 1 US gallon of tank water\u003c\/li\u003e\n\u003cli\u003eTarget reef magnesium range: 1200-1350 ppm\u003c\/li\u003e\n\u003cli\u003eMaximum recommended daily increase: 50 ppm\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: magnesium keeps calcium and alkalinity in balance in reef water — without enough of it, calcium and carbonate can precipitate out of solution instead of staying available for coral growth, which is why low magnesium is a common hidden cause of calcium or alkalinity readings that won't hold steady no matter how much is dosed. This pharmaceutical-based formula dissolves crystal clear with no residue.\u003c\/p\u003e\u003cp\u003eIncludes: 3 lb resealable bag of magnesium chloride powder. Requires Reef Endurance Magnesium Sulfate (sold separately) to complete the stock solution recipe.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598515756,"sku":"RE-MGCHL-B","price":18.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/re_magnesiumchloride_front.jpg?v=1787190585"},{"product_id":"reef-endurance-bulk-magnesium-chloride-30lbs-re-mgchl-xl","title":"Reef Endurance Bulk Magnesium Chloride 30lbs","description":"\u003cp\u003eReef Endurance Bulk Magnesium Chloride 30lbs is a pharmaceutical-grade magnesium chloride powder packed in a resealable 5-gallon bucket, used together with Reef Endurance Magnesium Sulfate to build magnesium stock solution for high-volume reef systems.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 30 lbs (13.6 kg) in a resealable 5-gallon bucket\u003c\/li\u003e\n\u003cli\u003eMix ratio (per 1 gallon RO\/DI water): 1181.25g magnesium chloride + 378g magnesium sulfate\u003c\/li\u003e\n\u003cli\u003eYields approximately 11.5 gallons of concentrated stock solution when paired with the matching magnesium sulfate\u003c\/li\u003e\n\u003cli\u003eDosing: 1 mL of stock solution raises magnesium approximately 14 ppm per 1 US gallon of tank water\u003c\/li\u003e\n\u003cli\u003eTarget reef magnesium range: 1200-1350 ppm\u003c\/li\u003e\n\u003cli\u003eMaximum recommended daily increase: 50 ppm\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: magnesium keeps calcium and alkalinity in balance in reef water — without enough of it, calcium and carbonate can precipitate out of solution instead of staying available for coral growth. A harmless calcium sulfate haze can form in the freshly mixed solution; that's expected and not a sign the batch is bad. Buying a 30 lb bucket instead of repeated small bags cuts the cost per gallon of stock solution for large systems.\u003c\/p\u003e\u003cp\u003eIncludes: 30 lb (5-gallon bucket) of magnesium chloride powder. Requires Reef Endurance Magnesium Sulfate (sold separately) to complete the stock solution recipe.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598548524,"sku":"RE-MGCHL-XL","price":157.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/reef_endurance_magnesium_chloride_30ibs.jpg?v=1787190585"},{"product_id":"reef-endurance-bulk-magnesium-sulfate-4lbs-re-mgslf-b","title":"Reef Endurance Bulk Magnesium Sulfate 4lbs","description":"\u003cp\u003eReef Endurance Bulk Magnesium Sulfate 4lbs is a pharmaceutical-grade magnesium sulfate powder for maintaining magnesium levels in reef aquariums, used together with Reef Endurance Magnesium Chloride to build a complete stock solution.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 4 lbs, resealable bag\u003c\/li\u003e\n\u003cli\u003eMix ratio (per 1 gallon RO\/DI water): 378g magnesium sulfate + 1181.25g magnesium chloride\u003c\/li\u003e\n\u003cli\u003eYields approximately 4.8 gallons of concentrated stock solution when paired with the matching magnesium chloride\u003c\/li\u003e\n\u003cli\u003eDosing: 1 mL of the combined stock solution raises magnesium approximately 14 ppm per 1 US gallon of tank water\u003c\/li\u003e\n\u003cli\u003eTarget reef magnesium range: 1200-1350 ppm\u003c\/li\u003e\n\u003cli\u003eMaximum recommended daily increase: 50 ppm\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: magnesium sulfate supplies the sulfate half of the magnesium recipe alongside magnesium chloride — dosing magnesium chloride alone would push chloride levels up faster than a salt mix replaces them, so the two-salt approach keeps the water's ionic balance closer to natural seawater while still restoring the magnesium that corals and coralline algae draw down.\u003c\/p\u003e\u003cp\u003eIncludes: 4 lb resealable bag of magnesium sulfate powder. Requires Reef Endurance Magnesium Chloride (sold separately) to complete the stock solution recipe.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000598581292,"sku":"RE-MGSLF-B","price":18.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/re_magnesiumsulfate_front.jpg?v=1787190586"},{"product_id":"reef-endurance-bulk-magnesium-sulfate-30lbs-re-mgslf-xl","title":"Reef Endurance Bulk Magnesium Sulfate 30lbs","description":"\u003cp\u003eReef Endurance Bulk Magnesium Sulfate 30lbs is a pharmaceutical-grade magnesium sulfate powder packed in a resealable 5-gallon bucket, used together with Reef Endurance Magnesium Chloride to build magnesium stock solution for high-volume reef systems.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 30 lbs (13.6 kg) in a resealable 5-gallon bucket\u003c\/li\u003e\n\u003cli\u003eMix ratio (per 1 gallon RO\/DI water): 378g magnesium sulfate + 1181.25g magnesium chloride\u003c\/li\u003e\n\u003cli\u003eYields approximately 36 gallons of concentrated stock solution when paired with the matching magnesium chloride\u003c\/li\u003e\n\u003cli\u003eDosing: 1 mL of the combined stock solution raises magnesium approximately 14 ppm per 1 US gallon of tank water\u003c\/li\u003e\n\u003cli\u003eTarget reef magnesium range: 1200-1350 ppm\u003c\/li\u003e\n\u003cli\u003eMaximum recommended daily increase: 50 ppm\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: magnesium sulfate supplies the sulfate half of the magnesium recipe alongside magnesium chloride, keeping the water's ionic balance closer to natural seawater while restoring the magnesium that corals and coralline algae draw down. Buying a 30 lb bucket instead of repeated small bags cuts the cost per gallon of stock solution for large systems.\u003c\/p\u003e\u003cp\u003eIncludes: 30 lb (5-gallon bucket) of magnesium sulfate powder. Requires Reef Endurance Magnesium Chloride (sold separately) to complete the stock solution recipe.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000600809516,"sku":"RE-MGSLF-XL","price":157.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/reef_endurance_magnesium_sulfate_30ibs.jpg?v=1787190657"},{"product_id":"reef-endurance-rox-0-8-carbon-1-gallon-re-roxcrb-lg","title":"Reef Endurance ROX 0.8 Carbon 1 gallon","description":"\u003cp\u003eReef Endurance ROX 0.8 Carbon 1 gallon is a pharmaceutical-grade extruded pellet activated carbon, acid-washed for purity, for polishing water and pulling yellowing compounds out of freshwater and marine aquariums.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eContainer size: 1 gallon of extruded carbon pellets\u003c\/li\u003e\n\u003cli\u003eSurface area (BET): 1,300 m2\/g; iodine number: 1000 minimum\u003c\/li\u003e\n\u003cli\u003eBall-pan hardness: 97 minimum; ash content: 1%; neutral pH\u003c\/li\u003e\n\u003cli\u003eDosage: 1 tablespoon per 10 gallons of tank water\u003c\/li\u003e\n\u003cli\u003eOne container holds enough carbon for a full dose in aquariums up to approximately 2,560 gallons combined\u003c\/li\u003e\n\u003cli\u003eReplace every two weeks, or sooner if clarity or odor declines\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: the high ball-pan hardness (97 min) keeps these pellets from crumbling into fine dust that leaches back through reactor screens, so this carbon needs only a brief rinse instead of the long pre-soak lower-grade carbons require. Its high surface area and iodine number pull yellowing compounds and medication residue out fast — don't run it right after a medication treatment, since it will also strip the medication itself.\u003c\/p\u003e\u003cp\u003eIncludes: 1 gallon of pharmaceutical-grade ROX 0.8 activated carbon pellets. Use in a media reactor, canister filter, or fine mesh bag under moderate flow.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000600875052,"sku":"RE-ROXCRB-LG","price":61.94,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/roxgraphic.jpg?v=1787190658"},{"product_id":"reef-endurance-rox-0-8-carbon-1-2-gallon-re-roxcrb-md","title":"Reef Endurance ROX 0.8 Carbon 1\/2 gallon","description":"\u003cp\u003eReef Endurance ROX 0.8 Carbon 1\/2 gallon is a pharmaceutical-grade extruded pellet activated carbon, acid-washed for purity, for polishing water and pulling yellowing compounds out of freshwater and marine aquariums.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eContainer size: 1\/2 gallon of extruded carbon pellets\u003c\/li\u003e\n\u003cli\u003eSurface area (BET): 1,300 m2\/g; iodine number: 1000 minimum\u003c\/li\u003e\n\u003cli\u003eBall-pan hardness: 97 minimum; ash content: 1%; neutral pH\u003c\/li\u003e\n\u003cli\u003eDosage: 1 tablespoon per 10 gallons of tank water\u003c\/li\u003e\n\u003cli\u003eOne container holds enough carbon for a full dose in aquariums up to approximately 1,280 gallons combined\u003c\/li\u003e\n\u003cli\u003eReplace every two weeks, or sooner if clarity or odor declines\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: the high ball-pan hardness (97 min) keeps these pellets from crumbling into fine dust that leaches back through reactor screens, so this carbon needs only a brief rinse instead of the long pre-soak lower-grade carbons require. Its high surface area and iodine number pull yellowing compounds and medication residue out fast — don't run it right after a medication treatment, since it will also strip the medication itself.\u003c\/p\u003e\u003cp\u003eIncludes: 1\/2 gallon of pharmaceutical-grade ROX 0.8 activated carbon pellets. Use in a media reactor, canister filter, or fine mesh bag under moderate flow.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000600940588,"sku":"RE-ROXCRB-MD","price":34.64,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/roxgraphic_651d7e03-1e9e-4910-8bf6-d02fc2ee97cc.jpg?v=1787190658"},{"product_id":"reef-endurance-rox-0-8-carbon-1-4-gallon-re-roxcrb-sm","title":"Reef Endurance ROX 0.8 Carbon 1\/4 gallon","description":"\u003cp\u003eReef Endurance ROX 0.8 Carbon 1\/4 gallon is a pharmaceutical-grade extruded pellet activated carbon, acid-washed for purity, for polishing water and pulling yellowing compounds out of freshwater and marine aquariums.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eContainer size: 1\/4 gallon of extruded carbon pellets\u003c\/li\u003e\n\u003cli\u003eSurface area (BET): 1,300 m2\/g; iodine number: 1000 minimum\u003c\/li\u003e\n\u003cli\u003eBall-pan hardness: 97 minimum; ash content: 1%; neutral pH\u003c\/li\u003e\n\u003cli\u003eDosage: 1 tablespoon per 10 gallons of tank water\u003c\/li\u003e\n\u003cli\u003eOne container holds enough carbon for a full dose in aquariums up to approximately 640 gallons combined\u003c\/li\u003e\n\u003cli\u003eReplace every two weeks, or sooner if clarity or odor declines\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: the high ball-pan hardness (97 min) keeps these pellets from crumbling into fine dust that leaches back through reactor screens, so this carbon needs only a brief rinse instead of the long pre-soak lower-grade carbons require. It's a good fit for nano and mid-size tanks that only need a small charge replaced every couple of weeks rather than a large bulk container — and don't run it right after a medication treatment, since it will also strip the medication itself.\u003c\/p\u003e\u003cp\u003eIncludes: 1\/4 gallon of pharmaceutical-grade ROX 0.8 activated carbon pellets. Use in a media reactor, canister filter, or fine mesh bag under moderate flow.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000600973356,"sku":"RE-ROXCRB-SM","price":23.09,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/roxgraphic_e5f4bc94-5895-4bfd-8411-bd6fae164502.jpg?v=1787190659"},{"product_id":"reef-endurance-rox-0-8-carbon-5-gallon-re-roxcrb-xl","title":"Reef Endurance ROX 0.8 Carbon 5 gallon","description":"\u003cp\u003eReef Endurance ROX 0.8 Carbon 5 gallon is a pharmaceutical-grade extruded pellet activated carbon, acid-washed for purity, packed in bulk for large systems and multi-tank fish rooms.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eContainer size: 5 gallon bucket of extruded carbon pellets\u003c\/li\u003e\n\u003cli\u003eSurface area (BET): 1,300 m2\/g; iodine number: 1000 minimum\u003c\/li\u003e\n\u003cli\u003eBall-pan hardness: 97 minimum; ash content: 1%; neutral pH\u003c\/li\u003e\n\u003cli\u003eDosage: 1 tablespoon per 10 gallons of tank water\u003c\/li\u003e\n\u003cli\u003eOne bucket holds enough carbon for a full dose in aquariums up to approximately 12,800 gallons combined\u003c\/li\u003e\n\u003cli\u003eReplace every two weeks, or sooner if clarity or odor declines\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: the high ball-pan hardness (97 min) keeps these pellets from crumbling into fine dust that leaches back through reactor screens, so this carbon needs only a brief rinse instead of the long pre-soak lower-grade carbons require. Buying a 5 gallon bucket instead of repeated small containers cuts the cost per dose for stores, frag farms, and multi-tank fish rooms cycling carbon every two weeks. Don't run it right after a medication treatment, since it will also strip the medication itself.\u003c\/p\u003e\u003cp\u003eIncludes: 5 gallon bucket of pharmaceutical-grade ROX 0.8 activated carbon pellets. Use in a media reactor, canister filter, or fine mesh bag under moderate flow.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000601038892,"sku":"RE-ROXCRB-XL","price":262.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/roxgraphic_69fcf5bc-a26c-4f67-bce0-a955fa7c703b.jpg?v=1787190659"},{"product_id":"reef-endurance-bulk-soda-ash-3-5lbs-re-sdash-b","title":"Reef Endurance Bulk Soda Ash 3.5lbs","description":"\u003cp\u003eReef Endurance Bulk Soda Ash 3.5lbs is a pharmaceutical-grade sodium carbonate powder for buffering and maintaining alkalinity in reef aquariums, packed as a resealable 3.5 lb bag.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 3.5 lbs, resealable bag\u003c\/li\u003e\n\u003cli\u003eMix ratio: 375g (about 1 cup) soda ash per 1 gallon RO\/DI water, yielding approximately 1.87 meq\/L alkalinity\u003c\/li\u003e\n\u003cli\u003eYields approximately 4.2 gallons of concentrated stock solution\u003c\/li\u003e\n\u003cli\u003eDosing: 46.4 mL of stock solution raises alkalinity approximately 1 dKH in a 65-gallon aquarium\u003c\/li\u003e\n\u003cli\u003eTarget reef alkalinity range: 8.0-12.0 dKH\u003c\/li\u003e\n\u003cli\u003eMaximum recommended daily increase: 1 dKH\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: soda ash (sodium carbonate) is the alkalinity buffer of choice when a reef tank's pH runs low, since it doesn't pull pH down the way sodium bicarbonate does. Pair it with Reef Endurance Calcium Chloride for a complete two-part dosing system, and if alkalinity won't hold steady, check that magnesium is in the 1200-1350 ppm range first — low magnesium is a common hidden cause.\u003c\/p\u003e\u003cp\u003eIncludes: 3.5 lb resealable bag of soda ash powder.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000601104428,"sku":"RE-SDASH-B","price":18.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/re_sodaash_front.jpg?v=1787190660"},{"product_id":"reef-endurance-bulk-soda-ash-25lbs-re-sdash-xl","title":"Reef Endurance Bulk Soda Ash 25lbs","description":"\u003cp\u003eReef Endurance Bulk Soda Ash 25lbs is a pharmaceutical-grade sodium carbonate powder for high-volume reef systems and multi-tank fish rooms that need alkalinity buffer stock solution in bulk.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eNet weight: 25 lbs, resealable bulk packaging\u003c\/li\u003e\n\u003cli\u003eMix ratio: 375g (about 1 cup) soda ash per 1 gallon RO\/DI water, yielding approximately 1.87 meq\/L alkalinity\u003c\/li\u003e\n\u003cli\u003eYields approximately 30 gallons of concentrated stock solution when fully mixed\u003c\/li\u003e\n\u003cli\u003eDosing: 46.4 mL of stock solution raises alkalinity approximately 1 dKH in a 65-gallon aquarium\u003c\/li\u003e\n\u003cli\u003eTarget reef alkalinity range: 8.0-12.0 dKH\u003c\/li\u003e\n\u003cli\u003eMaximum recommended daily increase: 1 dKH\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhy this matters: soda ash (sodium carbonate) is the alkalinity buffer of choice when a reef tank's pH runs low, since it doesn't pull pH down the way sodium bicarbonate does. Large systems and multi-tank operations burn through kH buffer fast, and a 25 lb bulk bag cuts the cost per gallon of stock solution versus repeated small bags. Pair it with Reef Endurance Calcium Chloride for a complete two-part dosing system.\u003c\/p\u003e\u003cp\u003eIncludes: 25 lb bulk bag of soda ash powder.\u003c\/p\u003e","brand":"Reef Endurance","offers":[{"title":"Default Title","offer_id":46000601137196,"sku":"RE-SDASH-XL","price":157.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/files\/reef_endurance_soda_ash_25ibs.jpg?v=1787190660"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0584\/4382\/5196\/collections\/re_calciumchloride_front.jpg?v=1794320468","url":"https:\/\/www.marineconceptsupply.com\/collections\/black-friday-2026-reef-endurance.oembed","provider":"Marine Concept Supply","version":"1.0","type":"link"}