{"product_id":"pond-filter-foam-replacement-packs-uk-universal-fit-fine-coarse-media-koi-pond","title":"Pond Filter Foam Replacement Packs UK | Universal Fit | Fine \u0026 Coarse Media | Koi Pond","description":"\u003cp\u003e\u003cstrong\u003ePond filter foam replacement packs are the fast, affordable way to restore your koi pond's water clarity and biological balance. Available in fine and coarse grades, our universal-fit foam sheets cut to any shape, reviving sluggish filters within hours. Suitable for all major filter brands, they provide both mechanical and biological filtration in one.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003ch2\u003eWhy Choose Our Pond Filter Foam Replacement Packs?\u003c\/h2\u003e\n\u003cp\u003eOver time, pond filter foam becomes clogged, compressed, and ineffective. Replacing your filter media is one of the single most impactful things you can do for water quality. Our premium replacement foam packs are engineered from open-cell polyurethane — the industry gold standard — offering exceptional dirt-trapping capacity whilst allowing beneficial bacteria colonies to thrive.\u003c\/p\u003e\n\n\u003ch3\u003eFine \u0026amp; Coarse Foam: A Two-Stage Filtration Powerhouse\u003c\/h3\u003e\n\u003cp\u003eEvery pack includes both fine and coarse foam grades. The \u003cstrong\u003ecoarse layer\u003c\/strong\u003e captures large debris, dead algae, fish waste, and leaf fragments before they break down and foul your water. The \u003cstrong\u003efine layer\u003c\/strong\u003e follows, polishing the water column and catching suspended particles that cause cloudiness. Together, they give you crystal-clear, healthy pond water.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eFine \u0026amp; coarse foam grades\u003c\/strong\u003e — two-stage mechanical + biological filtration\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eUniversal sizing\u003c\/strong\u003e — easily trimmed with scissors to fit any filter box\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eOpen-cell structure\u003c\/strong\u003e — maximises surface area for beneficial bacteria\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eKoi safe\u003c\/strong\u003e — no leaching chemicals, safe for all pond fish\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eDurable material\u003c\/strong\u003e — won't degrade quickly, long service life\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eUK garden tested\u003c\/strong\u003e — performs in variable British weather conditions\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eProduct Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003ctr\u003e\n\u003cth\u003eFeature\u003c\/th\u003e\n\u003cth\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003eOpen-cell polyurethane foam\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eGrades included\u003c\/td\u003e\n\u003ctd\u003eFine + Coarse (both in pack)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eFitting\u003c\/td\u003e\n\u003ctd\u003eUniversal — cut-to-fit\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eFiltration type\u003c\/td\u003e\n\u003ctd\u003eMechanical + biological\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eSafe for\u003c\/td\u003e\n\u003ctd\u003eKoi, goldfish, all pond fish\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003eRecommended replacement\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eHow to Install Your Replacement Filter Foam\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eSwitch off your pond pump before opening the filter.\u003c\/li\u003e\n  \u003cli\u003eRemove old foam and rinse the filter housing with pond water (never tap water — chlorine kills beneficial bacteria).\u003c\/li\u003e\n  \u003cli\u003eCut new foam sheets to size using sharp scissors.\u003c\/li\u003e\n  \u003cli\u003eInsert coarse foam first (nearest the pump inlet), then fine foam.\u003c\/li\u003e\n  \u003cli\u003eReassemble and restart your pump.\u003c\/li\u003e\n  \u003cli\u003eAllow 4–6 weeks for bacteria colonies to fully establish on new media.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\n\u003ch3\u003eHow often should I replace pond filter foam?\u003c\/h3\u003e\n\u003cp\u003eMost pond keepers replace filter foam every 6 to 12 months. Signs it's time include reduced flow, persistent green water despite cleaning, or visible foam breakdown. Always rinse (never replace) foam if it's only mildly dirty — full replacement is for when the media is permanently clogged or crumbling.\u003c\/p\u003e\n\n\u003ch3\u003eCan I use this foam in any pond filter?\u003c\/h3\u003e\n\u003cp\u003eYes. Our foam sheets are designed to be cut to any shape or size, making them compatible with virtually all box filters, barrel filters, and multi-bay filter systems on the UK market.\u003c\/p\u003e\n\n\u003ch3\u003eWill replacing filter foam crash my pond's nitrogen cycle?\u003c\/h3\u003e\n\u003cp\u003eTo minimise disruption, never replace all foam at once. Replace coarse and fine foam on alternate months so some established bacterial colonies remain active at all times.\u003c\/p\u003e\n\n\u003ch3\u003eIs this foam safe for koi and goldfish?\u003c\/h3\u003e\n\u003cp\u003eAbsolutely. Our foam contains no harmful plasticisers or chemicals. It is inert and non-toxic — completely safe for koi, goldfish, sturgeon, and all other pond fish.\u003c\/p\u003e\n\n\u003ch3\u003eWhat size do I need?\u003c\/h3\u003e\n\u003cp\u003eThe Medium Pack suits most hobby pond filters. The Large Pack is ideal for filters on ponds 5,000–15,000 litres. The XL Pack is designed for large koi ponds and professional-grade filter systems.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003e🚚 Free UK delivery | 📦 Dispatched within 1 business day | 💬 Expert pond advice available\u003c\/em\u003e\u003c\/p\u003e","brand":"PondLiners Co","offers":[{"title":"Medium Pack","offer_id":57667224568156,"sku":null,"price":78.0,"currency_code":"GBP","in_stock":true},{"title":"Large Pack","offer_id":57667224600924,"sku":null,"price":124.97,"currency_code":"GBP","in_stock":true},{"title":"XL Pack","offer_id":57667224633692,"sku":null,"price":179.97,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0889\/2035\/9260\/files\/4cf5bf3076417c070fb88ddba65baff1.jpg?v=1779043247","url":"https:\/\/www.pondlinersco.co.uk\/products\/pond-filter-foam-replacement-packs-uk-universal-fit-fine-coarse-media-koi-pond","provider":"PondLinersco.co.uk","version":"1.0","type":"link"}