{"product_id":"fluval-nitrate-cartridge-g3","title":"Fluval Nitrate Cartridge G3","description":"\u003cp\u003e\u003cstrong\u003eA drop-in nitrate scrubber sized specifically for the Fluval G3 filter.\u003c\/strong\u003e The Fluval Nitrate Cartridge G3 (Fluval part A421) is chemical filter media pre-loaded into a cartridge that seats directly into the G3 canister, rated to remove up to 13,000 mg of nitrate ion from freshwater aquariums before it's exhausted.\u003c\/p\u003e\n\u003ch3\u003eKey features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePurpose-built for the Fluval G3\u003c\/strong\u003e — drops straight into the G3's media stack; no repacking of loose resin.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemoves up to 13,000 mg of nitrate ion\u003c\/strong\u003e — aimed at keeping freshwater nitrate below the commonly recommended 20 mg\/L.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo cycle disruption\u003c\/strong\u003e — chemical media only; doesn't touch the biological or mechanical stages running alongside it in the G3.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpec\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFits\u003c\/td\u003e\n\u003ctd\u003eFluval G3 Advanced Filtration System\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eManufacturer part number\u003c\/td\u003e\n\u003ctd\u003eA421\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNitrate removal capacity\u003c\/td\u003e\n\u003ctd\u003eUp to 13,000 mg nitrate ion (freshwater)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMedia type\u003c\/td\u003e\n\u003ctd\u003eChemical (nitrate-adsorbing resin)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTarget parameter\u003c\/td\u003e\n\u003ctd\u003eKeep freshwater nitrate below approximately 20 mg\/L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eSuitable for, and not suitable for\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eSuitable for Fluval G3 filters running on freshwater aquariums with elevated nitrate.\u003c\/li\u003e\n\u003cli\u003eNot suitable as a substitute for regular water changes — it's rated as a supplementary reducer, not a replacement for husbandry.\u003c\/li\u003e\n\u003cli\u003eNot rated by Fluval for marine\/reef nitrate control at this capacity — treat it as a freshwater-specific cartridge.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCare and maintenance\u003c\/h3\u003e\n\u003cp\u003eFluval doesn't publish a fixed replacement calendar for this cartridge — capacity depends on your tank's nitrate load. Test freshwater nitrate periodically; once levels stop falling, or the cartridge has been running several months under normal freshwater bioload, replace it. If you're using it as a one-off fix for a nitrate spike rather than ongoing control, it can be removed once levels have settled back down.\u003c\/p\u003e\n\u003ch3\u003eWarranty and delivery\u003c\/h3\u003e\n\u003cp\u003eStandard parcel delivery. As a chemical filter media, it's a consumable and isn't covered by a separate warranty term beyond your rights under Australian Consumer Law.\u003c\/p\u003e\n\u003ch3\u003eCommon questions\u003c\/h3\u003e\n\u003ch4\u003eDoes this fit the Fluval G6?\u003c\/h4\u003e\n\u003cp\u003eNo — the G6 uses its own nitrate cartridge (Fluval A422), rated for a larger 24,000 mg capacity to match the G6's bigger media volume.\u003c\/p\u003e\n\u003ch4\u003eWill it affect my biological filtration?\u003c\/h4\u003e\n\u003cp\u003eNo — this is a chemical media cartridge that sits alongside the G3's biological and mechanical stages without disrupting them.\u003c\/p\u003e\n\u003ch4\u003eCan I use it in a marine tank?\u003c\/h4\u003e\n\u003cp\u003eFluval rates this cartridge specifically for freshwater nitrate removal; we don't have a published marine capacity figure for it.\u003c\/p\u003e","brand":"Fluval","offers":[{"title":"Default Title","offer_id":55293296967971,"sku":"FG01D","price":68.95,"currency_code":"AUD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0972\/7236\/5347\/files\/FG01d.png?v=1782879573","url":"https:\/\/nicksaquariumoceanariumterrarium.com.au\/products\/fluval-nitrate-cartridge-g3","provider":"Nicks Aquarium Oceanarium Terrarium","version":"1.0","type":"link"}