{"product_id":"seachem-reef-phosphorus-250ml","title":"Seachem Reef Phosphorus 250 mL – Reef Aquarium Phosphate Supplement","description":"\u003cp\u003eSeachem Reef Phosphorus 250 mL is a concentrated phosphorus supplement formulated for marine and reef aquariums with low phosphate levels. Phosphorus is an essential nutrient involved in coral and macroalgae metabolism, protein synthesis, growth, and coloration.\u003c\/p\u003e\n\u003cp\u003eReef Phosphorus provides a controlled way to increase phosphate without adding dissolved organic material. It is especially useful in low-nutrient reef aquariums where phosphate is consistently below the desired range despite regular feeding.\u003c\/p\u003e\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTargeted Phosphate Supplement:\u003c\/strong\u003e Provides a controlled source of phosphorus for marine and reef aquariums\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupports Coral Growth:\u003c\/strong\u003e Helps maintain phosphorus needed for normal coral metabolism and protein synthesis\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupports Coloration:\u003c\/strong\u003e Balanced nutrient availability can support healthy coloration in corals and macroalgae\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConcentrated Formula:\u003c\/strong\u003e Contains 3,500 mg\/L phosphate for precise manual or automated dosing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo Added Dissolved Organics:\u003c\/strong\u003e Raises phosphorus without introducing an organic nutrient source\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManual or Automated Dosing:\u003c\/strong\u003e May be added manually or used with a compatible dosing pump\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e250 mL Bottle:\u003c\/strong\u003e Convenient size for home reef aquariums and controlled nutrient management\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eProduct Information\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Seachem\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct:\u003c\/strong\u003e Reef Phosphorus\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize:\u003c\/strong\u003e 250 mL\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Reef aquarium phosphorus supplement\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConcentration:\u003c\/strong\u003e 3,500 mg\/L phosphate\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eElemental Phosphorus:\u003c\/strong\u003e 0.117%\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSource:\u003c\/strong\u003e Sodium phosphate\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAquarium Type:\u003c\/strong\u003e Marine and reef aquariums\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGeneral Phosphate Range:\u003c\/strong\u003e Approximately 0.02–0.05 mg\/L\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eBest Used For\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eReef aquariums with consistently low phosphate\u003c\/li\u003e\n\u003cli\u003eUltra-low nutrient reef systems\u003c\/li\u003e\n\u003cli\u003eSPS-dominant reef aquariums\u003c\/li\u003e\n\u003cli\u003eMixed reef aquariums\u003c\/li\u003e\n\u003cli\u003eSystems using aggressive nutrient export\u003c\/li\u003e\n\u003cli\u003eAquariums with heavy protein skimming or filtration\u003c\/li\u003e\n\u003cli\u003eReef systems using phosphate-removing media\u003c\/li\u003e\n\u003cli\u003eMaintaining balanced nitrogen and phosphorus availability\u003c\/li\u003e\n\u003cli\u003eSupporting coral and macroalgae nutrition\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eBeginner Dosing Directions\u003c\/h3\u003e\n\u003cp\u003eUse one-half capful, or 2.5 mL, of Seachem Reef Phosphorus for every 40 US gallons of aquarium water once weekly or as needed to maintain the desired phosphate concentration.\u003c\/p\u003e\n\u003cp\u003eThe beginner dose raises phosphate by approximately 0.05 mg\/L. Test the aquarium before dosing and avoid adding Reef Phosphorus when phosphate is already within or above the desired range.\u003c\/p\u003e\n\u003ch3\u003eAdvanced Dosing Formula\u003c\/h3\u003e\n\u003cp\u003eTo calculate a specific phosphate increase, use Seachem’s dosing formula:\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e0.31 × aquarium volume in liters × desired phosphate increase in mg\/L = milliliters of Reef Phosphorus\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFor example, raising phosphate by 0.05 mg\/L in a 160-liter aquarium requires approximately 2.5 mL of Reef Phosphorus.\u003c\/p\u003e\n\u003cp\u003eOne US gallon equals approximately 3.8 liters. Use the aquarium’s estimated actual water volume after accounting for rock, substrate, equipment, and displacement.\u003c\/p\u003e\n\u003ch3\u003eApproximate Dosing Examples\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e10 Gallons:\u003c\/strong\u003e Approximately 0.63 mL raises phosphate by about 0.05 mg\/L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e20 Gallons:\u003c\/strong\u003e Approximately 1.25 mL raises phosphate by about 0.05 mg\/L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e40 Gallons:\u003c\/strong\u003e 2.5 mL raises phosphate by about 0.05 mg\/L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e75 Gallons:\u003c\/strong\u003e Approximately 4.7 mL raises phosphate by about 0.05 mg\/L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e100 Gallons:\u003c\/strong\u003e Approximately 6.25 mL raises phosphate by about 0.05 mg\/L\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThese are proportional estimates based on Seachem’s beginner dose. Test before and after dosing rather than relying only on calculated values.\u003c\/p\u003e\n\u003ch3\u003eTesting \u0026amp; Target Levels\u003c\/h3\u003e\n\u003cp\u003eSeachem states that ideal phosphate levels vary between aquariums but generally fall between approximately 0.02 and 0.05 mg\/L phosphate. The appropriate level depends on coral demand, feeding, nutrient export, algae growth, and the overall balance of the aquarium.\u003c\/p\u003e\n\u003cp\u003eRaise phosphate slowly over several days when levels are extremely low. Corals, bacteria, algae, and other organisms may consume phosphorus quickly, particularly in nutrient-limited systems.\u003c\/p\u003e\n\u003cp\u003eTest regularly until a consistent dosing routine maintains a stable concentration. Avoid making large corrections based on a single test result.\u003c\/p\u003e\n\u003ch3\u003eWhy Phosphorus Matters\u003c\/h3\u003e\n\u003cp\u003ePhosphorus is required for essential biological processes, including energy transfer, protein synthesis, cellular activity, and growth. Corals and macroalgae require phosphorus along with nitrogen and other nutrients.\u003c\/p\u003e\n\u003cp\u003eExcess phosphate may contribute to nuisance algae or interfere with reef aquarium management, but phosphate levels that remain too low can also limit biological growth. Reef Phosphorus allows aquarists to add a measured amount when testing confirms supplementation is appropriate.\u003c\/p\u003e\n\u003ch3\u003eBalancing Nitrogen \u0026amp; Phosphorus\u003c\/h3\u003e\n\u003cp\u003ePhosphate should not be managed without considering nitrogen availability. A reef aquarium may have low phosphate, low nitrate, or an imbalance between the two nutrients.\u003c\/p\u003e\n\u003cp\u003eSeachem recommends using Reef Nitrogen when nitrogen supplementation is also required. Test both nitrate and phosphate before adjusting either nutrient, and make gradual changes based on the aquarium’s response.\u003c\/p\u003e\n\u003ch3\u003eDosing Tips\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eTest phosphate before every initial adjustment\u003c\/li\u003e\n\u003cli\u003eUse a reliable low-range marine phosphate test\u003c\/li\u003e\n\u003cli\u003eCalculate dosage using actual aquarium water volume\u003c\/li\u003e\n\u003cli\u003eRaise very low phosphate gradually over several days\u003c\/li\u003e\n\u003cli\u003eUse a dosing syringe for amounts smaller than one capful\u003c\/li\u003e\n\u003cli\u003eAdd the supplement to a high-flow area of the aquarium\u003c\/li\u003e\n\u003cli\u003eMonitor nitrate and phosphate together\u003c\/li\u003e\n\u003cli\u003eReduce or stop dosing if phosphate continues to rise\u003c\/li\u003e\n\u003cli\u003eReview phosphate-removing media if supplementation is repeatedly required\u003c\/li\u003e\n\u003cli\u003eKeep a dosing and testing log to identify the aquarium’s consumption rate\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eImportant Reef Aquarium Note\u003c\/h3\u003e\n\u003cp\u003eReef Phosphorus should be used only when testing confirms that phosphate supplementation is needed. Pale coral coloration, slow growth, reduced polyp extension, or tissue problems can have many causes and do not independently confirm phosphorus deficiency.\u003c\/p\u003e\n\u003cp\u003eCheck salinity, temperature, alkalinity, calcium, magnesium, nitrate, phosphate, lighting, water flow, pests, and overall aquarium stability before assuming that low phosphorus is the primary problem.\u003c\/p\u003e\n\u003cp\u003eOverdosing phosphate may contribute to nuisance algae growth or unwanted nutrient accumulation. Dose conservatively and allow time for the aquarium to respond.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is Seachem Reef Phosphorus used for?\u003c\/strong\u003e\u003cbr\u003eReef Phosphorus is used to increase phosphate in marine and reef aquariums where testing confirms that phosphorus levels are too low.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow much Reef Phosphorus should I use?\u003c\/strong\u003e\u003cbr\u003eThe beginner dose is 2.5 mL per 40 US gallons once weekly or as needed. This raises phosphate by approximately 0.05 mg\/L.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat phosphate level does Seachem recommend?\u003c\/strong\u003e\u003cbr\u003eSeachem states that ideal levels vary but generally range from approximately 0.02 to 0.05 mg\/L phosphate.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes 1 mL per 20 gallons raise phosphate by 0.02 ppm?\u003c\/strong\u003e\u003cbr\u003eNo. Based on Seachem’s official concentration, approximately 1.25 mL per 20 gallons raises phosphate by about 0.05 mg\/L. One milliliter per 20 gallons would raise it by approximately 0.04 mg\/L.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy would a reef aquarium need added phosphate?\u003c\/strong\u003e\u003cbr\u003ePhosphorus may become limited in aquariums with aggressive nutrient export, low feeding, strong protein skimming, phosphate-removing media, or high biological consumption.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs Reef Phosphorus a phosphate remover?\u003c\/strong\u003e\u003cbr\u003eNo. Reef Phosphorus adds phosphate. Products such as PhosGuard, PhosBond, or other phosphate-removing media serve the opposite purpose.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan Reef Phosphorus cause algae growth?\u003c\/strong\u003e\u003cbr\u003eExcessive phosphate may contribute to nuisance algae. Test regularly and add only enough product to maintain the desired concentration.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan it be used in an SPS reef aquarium?\u003c\/strong\u003e\u003cbr\u003eYes. It may be used in SPS systems when testing confirms that phosphate is below the desired level. Raise the concentration gradually and monitor coral response.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan it be used in a mixed reef aquarium?\u003c\/strong\u003e\u003cbr\u003eYes. Reef Phosphorus may be used in mixed reef systems when phosphate supplementation is needed and dosing is based on accurate testing.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eShould I test nitrate too?\u003c\/strong\u003e\u003cbr\u003eYes. Nitrogen and phosphorus availability should be considered together because an imbalance may limit coral or macroalgae growth.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan Reef Phosphorus be used with an automatic doser?\u003c\/strong\u003e\u003cbr\u003eYes. Seachem states that the product may be manually dosed or used with a compatible dosing system to maintain a stable concentration.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eShould I stop using phosphate-removing media?\u003c\/strong\u003e\u003cbr\u003eReview the need for phosphate-removing media if phosphate remains too low. Adding Reef Phosphorus while aggressively removing phosphate may create an inefficient dosing cycle.\u003c\/p\u003e\n\u003ch3\u003eAvailable at Tropical Treasures Wyo\u003c\/h3\u003e\n\u003cp\u003eSeachem Reef Phosphorus 250 mL provides a concentrated phosphate source for reef aquariums with confirmed low phosphorus levels. Visit Tropical Treasures Wyo in Cheyenne, Wyoming, to shop Seachem reef supplements, phosphate and nitrate test kits, dosing supplies, filtration media, reef foods, and aquarium care essentials.\u003c\/p\u003e","brand":"Tropical Treasures Wyo LLC","offers":[{"title":"Default Title","offer_id":53003265605845,"sku":null,"price":7.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0670\/4545\/8133\/files\/SC01296-2T.png?v=1784989344","url":"https:\/\/tropicaltreasureswyo.com\/products\/seachem-reef-phosphorus-250ml","provider":"Tropical Treasures Wyo LLC","version":"1.0","type":"link"}