{"product_id":"api-marine-algaefix-473ml","title":"API Marine Algaefix 473ml","description":"\u003cp\u003e\u003cstrong\u003eControls nuisance algae in reef tanks without harming the reef.\u003c\/strong\u003e API Marine AlgaeFix treats string, hair, fuzz and other nuisance algae in marine aquariums, and is labelled safe for use in systems that hold live corals and invertebrates. It's an aeration-friendly liquid dosed straight into the tank, sold here in a 473 mL (16 fl oz) bottle.\u003c\/p\u003e\n\n\u003ch3\u003eKey features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eControls nuisance marine algae\u003c\/strong\u003e — targeted at hair, string and fuzz algae fouling glass, rock and décor.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLabelled safe with live corals and invertebrates\u003c\/strong\u003e — API states it will not harm snails, clams, scallops, shrimp, anemones, sea cucumbers, feather dusters, coralline algae, soft corals or hard corals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSimple dosing\u003c\/strong\u003e — 1 mL per 10 US gallons (37.9 L), repeated every three days until the algae is controlled, then once a week to maintain it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWorks out to under 1c per litre\u003c\/strong\u003e of tank water treated, based on the manufacturer's stated coverage and the current price.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e473 mL (16 fl oz) bottle\u003c\/strong\u003e — API states this treats up to 4,800 US gallons (≈18,170 L) as a single dose; a tank dosed repeatedly every three days will use the bottle faster than that figure implies.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow to use it\u003c\/h3\u003e\n\u003cp\u003eReproduced from API's label directions:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eInitial treatment: 1 mL per 10 US gallons (37.9 L), or 5 mL per 50 US gallons (189 L), added directly to the aquarium.\u003c\/li\u003e\n\u003cli\u003eRepeat this dose every three days until the algae is under control.\u003c\/li\u003e\n\u003cli\u003eOnce controlled, switch to one maintenance dose per week at the same rate.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eAPI Marine AlgaeFix treats the algae that's already growing — it doesn't remove the phosphate or nitrate feeding it. Pairing it with regular water changes and nutrient export (a protein skimmer, GFO, or a nitrate\/phosphate reducer) stops the algae coming straight back once dosing stops.\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eAPI (Mars Fishcare)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBottle size\u003c\/th\u003e\n\u003ctd\u003e473 mL (16 fl oz)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eActive ingredient\u003c\/th\u003e\n\u003ctd\u003ePoly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene dichloride]\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eActive ingredient concentration\u003c\/th\u003e\n\u003ctd\u003eNot confirmed for this specific marine formulation — see Ingredients below\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDose rate\u003c\/th\u003e\n\u003ctd\u003e1 mL per 10 US gallons (37.9 L)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDosing schedule\u003c\/th\u003e\n\u003ctd\u003eEvery 3 days until controlled, then weekly for maintenance\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eManufacturer-stated coverage\u003c\/th\u003e\n\u003ctd\u003eUp to 4,800 US gallons (≈18,170 L) as a single dose\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWater type\u003c\/th\u003e\n\u003ctd\u003eMarine and reef aquariums\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eInvertebrate and coral safety\u003c\/th\u003e\n\u003ctd\u003eLabelled safe with live corals and invertebrates, dosed as directed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFreight\u003c\/th\u003e\n\u003ctd\u003eStandard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\n\u003ch3\u003eSuitable for, and not suitable for\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eSuitable for:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eMarine fish-only and reef aquariums with nuisance hair, string or fuzz algae\u003c\/li\u003e\n\u003cli\u003eSystems that hold live corals, snails, clams, shrimp, anemones and other invertebrates, dosed at the labelled rate\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eNot suitable for:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eFreshwater aquariums — use API Freshwater AlgaeFix instead, which is a different product with its own label\u003c\/li\u003e\n\u003cli\u003eReplacing nutrient control — it treats the algae, not the phosphate or nitrate feeding it\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eIngredients\u003c\/h3\u003e\n\u003cp\u003eAPI's product listing names the active ingredient as Poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene dichloride], a polymer algaecide. A published EPA pesticide label for API's Algae Fix product line states this active at 4.50%, but that label could not be confirmed as specific to the Marine AlgaeFix formulation sold here rather than a related freshwater or pond product in the same range, so the percentage is not stated as fact on this page. Checked 7 August 2026.\u003c\/p\u003e\n\n\u003ch3\u003eSafety and handling\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eKeep out of reach of children.\u003c\/li\u003e\n\u003cli\u003eEnsure strong aeration while dosing — algae die-off can draw down oxygen.\u003c\/li\u003e\n\u003cli\u003eDo not exceed the maintenance dose without confirming your tank's response first.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eGoes well with\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/red-sea-marine-care-multi-test-kit\"\u003eRed Sea Marine Care Multi Test Kit\u003c\/a\u003e — check phosphate and nitrate to find what's actually feeding the algae.\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/seachem-prime\"\u003eSeachem Prime\u003c\/a\u003e — for conditioning the water changes that support nutrient export alongside dosing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWarranty and delivery\u003c\/h3\u003e\n\u003cp\u003eThis is a consumable, so no manufacturer warranty period applies. That does not affect your rights under the Australian Consumer Law: if the product is faulty, unsafe or not as described, you are entitled to a remedy.\u003c\/p\u003e\n\u003cp\u003eShips as standard freight.\u003c\/p\u003e\n\n\u003ch3\u003eCommon questions\u003c\/h3\u003e\n\u003ch4\u003eIs API Marine AlgaeFix safe for my reef tank?\u003c\/h4\u003e\n\u003cp\u003eAPI labels it safe for use in marine aquariums containing live corals, invertebrates and fish, stating it will not harm snails, clams, scallops, shrimp, anemones, sea cucumbers, feather dusters, coralline algae, soft corals or hard corals when dosed as directed.\u003c\/p\u003e\n\u003ch4\u003eHow often do I dose it?\u003c\/h4\u003e\n\u003cp\u003eEvery three days until the algae is under control, then once a week as a maintenance dose, at 1 mL per 10 US gallons (37.9 L) each time.\u003c\/p\u003e\n\u003ch4\u003eWill the algae come back once I stop dosing?\u003c\/h4\u003e\n\u003cp\u003eIt can, if the phosphate or nitrate feeding it hasn't been addressed. AlgaeFix treats the algae itself; pairing it with water changes and nutrient export gives a longer-lasting result.\u003c\/p\u003e\n\u003ch4\u003eCan I use the freshwater AlgaeFix in my marine tank instead?\u003c\/h4\u003e\n\u003cp\u003eNo. API sells separate freshwater and marine formulations with their own labels and dose rates — use the one labelled for your water type.\u003c\/p\u003e\n\u003ch4\u003eHow long will one bottle last?\u003c\/h4\u003e\n\u003cp\u003eAPI states the 473 mL bottle treats up to 4,800 US gallons (≈18,170 L) as a single dose. Because the label calls for repeat dosing every three days during initial treatment, an actively-treated tank will use the bottle faster than that headline figure suggests.\u003c\/p\u003e","brand":"API","offers":[{"title":"Default Title","offer_id":54774195749155,"sku":null,"price":78.95,"currency_code":"AUD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0972\/7236\/5347\/files\/api-marine-algaefix-473ml-42333612933411.webp?v=1790237814","url":"https:\/\/nicksaquariumoceanariumterrarium.com.au\/products\/api-marine-algaefix-473ml","provider":"Nicks AOT","version":"1.0","type":"link"}