{"product_id":"seachem-phosguard","title":"Seachem PhosGuard","description":"\u003cp\u003e\u003cstrong\u003eStrips phosphate and silicate before they feed algae, in fresh or marine water.\u003c\/strong\u003e Seachem PhosGuard is a spherical, high-porosity aluminium oxide (alumina) media that binds phosphate and silicate on contact, run loose in a reactor or filter bag anywhere flow passes through it.\u003c\/p\u003e\n\u003cp\u003ePhosGuard suits reef tanks chasing lower nutrients for coral colour, planted and community freshwater tanks fighting nuisance algae, and any tank on tap water carrying silicate or phosphate. It is not recommended for freshwater aquariums buffered with a phosphate-based pH buffer, since the media will strip the buffer along with the nuisance nutrient.\u003c\/p\u003e\n\u003ch3\u003eKey features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBead-shaped alumina media\u003c\/strong\u003e — spherical form keeps flow even through a reactor or media bag, instead of channelling around a clump of dust.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBinds phosphate and silicate together\u003c\/strong\u003e — one media handles both of the nutrients that drive nuisance algae and diatoms.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e0.87 mg phosphate per gram\u003c\/strong\u003e — the working capacity Seachem publishes for PhosGuard's alumina base.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFresh and marine safe\u003c\/strong\u003e — the same media works across both water types, at different dose rates (see Directions).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFrom 2.5c per litre treated\u003c\/strong\u003e in the 4 L pack — see the size comparison below.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eContinuous or intermittent use\u003c\/strong\u003e — leave it running, or dose it in bursts ahead of a livestock introduction or a coral colouring push.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eMedia\u003c\/th\u003e\n\u003ctd\u003eAluminium oxide (alumina), spherical beads\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBinding capacity\u003c\/th\u003e\n\u003ctd\u003e0.87 mg phosphate per gram of media\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDose rate\u003c\/th\u003e\n\u003ctd\u003e85 mL per 200 L saltwater, or 85 mL per 400 L freshwater\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWater type\u003c\/th\u003e\n\u003ctd\u003eFreshwater and saltwater (not phosphate-buffered freshwater)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eUse\u003c\/th\u003e\n\u003ctd\u003eReactor, canister filter, or media bag in a high-flow area\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eWhich size do I need?\u003c\/h3\u003e\n\u003cp\u003ePhosGuard gets cheaper per litre treated the larger the pack — but not evenly. The jump from 100 mL to 500 mL more than halves the cost per litre; past 1 L, the saving per step is smaller.\u003c\/p\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003ePack size\u003c\/th\u003e\n\u003cth\u003ePrice\u003c\/th\u003e\n\u003cth\u003eTreats (saltwater)\u003c\/th\u003e\n\u003cth\u003eCost per litre treated\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e100 mL\u003c\/td\u003e\n\u003ctd\u003e$21.95\u003c\/td\u003e\n\u003ctd\u003e≈235 L\u003c\/td\u003e\n\u003ctd\u003e9.3c per litre\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e250 mL\u003c\/td\u003e\n\u003ctd\u003e$26.95\u003c\/td\u003e\n\u003ctd\u003e≈588 L\u003c\/td\u003e\n\u003ctd\u003e4.5c per litre\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e500 mL\u003c\/td\u003e\n\u003ctd\u003e$45.95\u003c\/td\u003e\n\u003ctd\u003e≈1,176 L\u003c\/td\u003e\n\u003ctd\u003e3.9c per litre\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e1 L\u003c\/td\u003e\n\u003ctd\u003e$75.95\u003c\/td\u003e\n\u003ctd\u003e≈2,353 L\u003c\/td\u003e\n\u003ctd\u003e3.2c per litre\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2 L\u003c\/td\u003e\n\u003ctd\u003e$133.95\u003c\/td\u003e\n\u003ctd\u003e≈4,706 L\u003c\/td\u003e\n\u003ctd\u003e2.8c per litre\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e4 L\u003c\/td\u003e\n\u003ctd\u003e$235.95\u003c\/td\u003e\n\u003ctd\u003e≈9,412 L\u003c\/td\u003e\n\u003ctd\u003e2.5c per litre\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003eFreshwater volumes treated are roughly double the saltwater figures above, since PhosGuard is dosed lighter in freshwater. The litres above use the saltwater dose, the more conservative of the two.\u003c\/p\u003e\n\u003ch3\u003eSuitable for, and not suitable for\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSuitable for:\u003c\/strong\u003e reef and FOWLR marine tanks, planted and community freshwater tanks, and any system where tap water or feeding is pushing phosphate or silicate up.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot suitable for:\u003c\/strong\u003e freshwater aquariums dosed with a phosphate-based pH buffer — PhosGuard will strip the buffer itself, not just the excess nutrient. Not a substitute for regular water changes or export via protein skimming.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eDirections and care\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003ePre-wet by adding the media to roughly double its volume of fresh water and rinsing before use — it can generate a little heat on first contact with water, which is normal.\u003c\/li\u003e\n\u003cli\u003ePosition it in flow without letting it tumble: a reactor, canister filter media basket, or a filter bag in a high-flow trickle area all work. Tumbling grinds the beads and shortens their working life.\u003c\/li\u003e\n\u003cli\u003eLeave in place for around 4 days, then test phosphate and silicate. If levels haven't dropped to roughly 0.02 mg\/L, the media is exhausted and it's time to replace it; if levels are still falling, leave it running.\u003c\/li\u003e\n\u003cli\u003eCan be run continuously or in short bursts, depending on how hard you're chasing a number.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSafety\u003c\/h3\u003e\n\u003cp\u003ePhosGuard can generate mild heat on first contact with water during pre-wetting — this is expected, not a fault. It is not a medication and carries no livestock warnings beyond the phosphate-buffer note above.\u003c\/p\u003e\n\u003ch3\u003eGoes well with\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eA phosphate and silicate test kit\u003c\/strong\u003e — to know when the media is exhausted rather than guessing on a calendar.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA media reactor or filter bag\u003c\/strong\u003e — for the even flow the beads need to work without tumbling.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeachem PhosNet\u003c\/strong\u003e — a higher-capacity synthetic GFO alternative where a smaller footprint or heavier phosphate load is the priority.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWarranty and delivery\u003c\/h3\u003e\n\u003cp\u003eCovered by Seachem's standard quality guarantee in addition to your rights under Australian Consumer Law. Standard shipping applies to all pack sizes; no cold chain or dangerous goods handling required.\u003c\/p\u003e\n\u003ch3\u003eCommon questions\u003c\/h3\u003e\n\u003ch4\u003eHow long does one dose of PhosGuard last?\u003c\/h4\u003e\n\u003cp\u003eThere's no fixed timeframe — it depends on how much phosphate and silicate is entering the tank. Start checking at around 4 days and replace once test readings stop dropping.\u003c\/p\u003e\n\u003ch4\u003eCan I run PhosGuard and carbon in the same reactor?\u003c\/h4\u003e\n\u003cp\u003eYes, though many aquarists run them in separate chambers or bags so each media gets even flow rather than competing for contact time.\u003c\/p\u003e\n\u003ch4\u003eWill PhosGuard affect my freshwater pH buffer?\u003c\/h4\u003e\n\u003cp\u003eIf your buffer is phosphate-based, yes — PhosGuard will strip it along with any excess phosphate. That's why it's not recommended for phosphate-buffered freshwater setups.\u003c\/p\u003e\n\u003ch4\u003eIs PhosGuard reef safe?\u003c\/h4\u003e\n\u003cp\u003eYes, it's widely used in reef tanks specifically to keep phosphate and silicate low for coral colour and to limit nuisance algae.\u003c\/p\u003e\n\u003ch4\u003eDo I need a reactor, or can I just drop it in the filter?\u003c\/h4\u003e\n\u003cp\u003eA reactor or filter bag in a high-flow area both work. What matters is that the media sits in flow without tumbling — loose in an open sump is the one placement to avoid.\u003c\/p\u003e","brand":"Seachem","offers":[{"title":"100 mL","offer_id":55244184715555,"sku":null,"price":21.95,"currency_code":"AUD","in_stock":true},{"title":"250 mL","offer_id":55244184748323,"sku":null,"price":26.95,"currency_code":"AUD","in_stock":true},{"title":"500 mL","offer_id":55244184781091,"sku":null,"price":45.95,"currency_code":"AUD","in_stock":true},{"title":"1 L","offer_id":55244184813859,"sku":null,"price":75.95,"currency_code":"AUD","in_stock":true},{"title":"2 L","offer_id":55244184846627,"sku":null,"price":133.95,"currency_code":"AUD","in_stock":true},{"title":"4 L","offer_id":55244184879395,"sku":null,"price":235.95,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0972\/7236\/5347\/files\/0189-phosguard-4-l_cc408caf-7f88-4f65-a837-ce42ad64e408.png?v=1782710765","url":"https:\/\/nicksaquariumoceanariumterrarium.com.au\/products\/seachem-phosguard","provider":"Nicks Aquarium Oceanarium Terrarium","version":"1.0","type":"link"}