{"product_id":"aquael-check-valve-non-return-valve-for-4-6-mm-air-tubing","title":"Aquael Check Valve – Non-Return Valve for 4\/6 mm Air Tubing","description":"\u003cp\u003e\u003cstrong\u003eThe Aquael Check Valve is a non-return valve for standard 4\/6 mm aquarium air tubing. It lets air flow from the pump to the aquarium and blocks water from flowing back down the tube.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIf an air pump stands lower than the aquarium and the power goes off, water can siphon back through the tubing, flood the pump and leak onto the floor. A check valve costs very little and prevents exactly that.\u003c\/p\u003e\n\n\u003ch3\u003eKey specifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eTubing\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e4\/6 mm air tubing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFunction\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCheck valve (non-return valve)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eUse\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eAir lines for airstones, sponge filters and moving bed filters\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eHow to install\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003eCut the air tubing a short distance from the pump.\u003c\/li\u003e\n\u003cli\u003ePush both ends onto the valve.\u003c\/li\u003e\n\u003cli\u003eMake sure the valve's direction marking points towards the aquarium.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eFrequently asked questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use it for CO2?\u003c\/strong\u003e\u003cbr\u003eFor CO2 we recommend a stainless steel valve such as the \u003ca href=\"\/bg\/products\/me-co2-safety-flow-steel\"\u003eMe CO2 Safety Flow Steel\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp\u003eNeed tubing? See \u003ca href=\"\/bg\/products\/air-tube-4-6mm-3m\"\u003eAir Tube 4\/6 mm – 3 m\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eBrand:\u003c\/strong\u003e Aquael  |  \u003cstrong\u003eCategory:\u003c\/strong\u003e Air line accessory\u003c\/p\u003e","brand":"AquaEL","offers":[{"title":"Default Title","offer_id":63872335216970,"sku":null,"price":2.99,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0771\/3685\/5370\/files\/Screenshot2026-10-10142536.jpg?v=1791631572","url":"https:\/\/aquarium-boutique.com\/bg\/products\/aquael-check-valve-non-return-valve-for-4-6-mm-air-tubing","provider":"Aquarium Boutique","version":"1.0","type":"link"}