{"product_id":"black-knight-filter-brush-4-inch-x-9-inch-10cm-x-23cm","title":"Black Knight Filter Brush -  4 inch x 9 inch (10cm x 23cm)","description":"\u003cp\u003e\u003cstrong\u003eBlack Knight Filter Brush - 4 inch x 9 inch (10cm x 23cm)\u003c\/strong\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003cbr\u003eBlack Knight filter brushes are made from the very highest quality Hydrotek polypropylene twisted into two stainless steel wires to form a cylindrical brush with a loop at one end for hanging. The other end is capped with a plastic knob for safety. They last indefinitely and are the easiest to use, most efficient and most cost-effective pond filter medium you can buy. Our brushes are used in filtration systems in fish farms, hatcheries, public aquaria, domestic fish ponds and research institutes in this country and abroad. No other filter medium is as widely used or has been as extensively tested and proved.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow to use Black Knight Filter Brushes\u003c\/strong\u003e\u003cbr\u003eIf you have a small pond with a few goldfish and a couple of Koi then a single chamber with three to six lines of brushes will be ideal. For a more demanding situation, it will be necessary to use a much larger chamber or to link two or three together. These can all contain brushes or you can use them in the first and second chambers and then other media, such as \u003ca href=\"\/products\/evolution-aqua-kplus-media-50-litre-bag#accordionTop\"\u003eKplus\u003c\/a\u003e or \u003ca href=\"\/collections\/d-i-y-filter-foam-sets\"\u003efoam\u003c\/a\u003e, in the last chamber. When designing your layout remember to include an overlap so the brushes interlink. \u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eBlack Knight Filter Brush Benefits\u003c\/strong\u003e\u003cbr\u003e• Great for both biological and mechanical filtration\u003cbr\u003e• Low unit cost\u003cbr\u003e• Easy to clean\u003cbr\u003e• Very effective at reducing foam filter cleaning\u003cbr\u003e• Massive surface area for biological colonisation\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eBlack Knight Filter Brush Sizes\u003c\/strong\u003e\u003cbr\u003eThe measurements given refer to the main body of the brush, every brush has a 3 inch (8cm) top ring and a ¾ inch (1.5cm) bottom spike\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e4 inch (10cm) Filter Brushes\u003c\/strong\u003e\u003cbr\u003e• 4\" x 9\" ( 10cm x 23cm)\u003cbr\u003e• 4\" x 12\" (10cm x 30cm)\u003cbr\u003e• 4\" x 16\" ( 10cm x 40cm)\u003cbr\u003e• 4\" x 20\" ( 10cm x 50cm)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e6 inch (15cm) Filter Brushes\u003c\/strong\u003e\u003cbr\u003e• 6\" x 12\" (15cm x 30cm)\u003cbr\u003e• 6\" x 16\" ( 15cm x 40cm)\u003cbr\u003e• 6\" x 20\" ( 15cm x 50cm)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e8 inch (20cm) Filter Brushes\u003c\/strong\u003e\u003cbr\u003e• 8\" x 16\" (20cm x 40cm)\u003c\/p\u003e","brand":"Black Knight","offers":[{"title":"Default Title","offer_id":49214677287186,"sku":"BKS001","price":1.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0854\/4914\/6642\/files\/P_Black-Knight-Replacement-Pond-Filter-Brush.jpg?v=1742227727","url":"https:\/\/www.watergardeningdirect.com\/products\/black-knight-filter-brush-4-inch-x-9-inch-10cm-x-23cm","provider":"Water Gardening Direct Ltd","version":"1.0","type":"link"}