{"product_id":"sp-bx-ctx-e-diffuser-small","title":"Astralpool Diffuser Small - BX \/ CTX 180-400 \/ E-Series 40071A","description":"\u003c!-- HASP-FLP-1.0 | SKU SP40071A | rule CTX-1.0 | canary: diffuser-small-echo --\u003e\n\u003ch3\u003eAstralpool Diffuser Small - BX \/ CTX 180-400 \/ E-Series 40071A\u003c\/h3\u003e\n\u003cp\u003eThis is the genuine Astralpool \u003cstrong\u003esmall\u003c\/strong\u003e diffuser, part number \u003cstrong\u003e40071A\u003c\/strong\u003e (supplied as SP40071A). The diffuser sits over the impeller and directs flow into the volute. Astralpool fits two sizes across this pump family, and they are not interchangeable — this is the small one, for the \u003cstrong\u003eCTX 180, 280, 360 and 400\u003c\/strong\u003e, the \u003cstrong\u003eViron XT P320\u003c\/strong\u003e, the \u003cstrong\u003eBX \/ E-series\u003c\/strong\u003e and the P280 \/ P300 pumps.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan style=\"color: rgb(43, 0, 255);\"\u003e\u003cstrong\u003ePhysically Stocked, unlike most \"drop-shipping\" websites.\u003c\/strong\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"color: rgb(43, 0, 255);\"\u003e\u003cstrong\u003eShipped from VIC, NSW, WA, QLD\u003c\/strong\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eLarge or Small? Get This Right First\u003c\/h3\u003e\n\u003cp\u003eThe single most common diffuser mistake is ordering the wrong size, because both look similar in a photo. Match your pump to the correct part:\u003c\/p\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003ePump\u003c\/th\u003e\n\u003cth\u003eDiffuser\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCTX 180 \/ 280 \/ 360 \/ 400, BX \/ E small, P280 \/ P300\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003e40071A — small, this product\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCTX 500 \/ 610, Viron XT P520, BX large\u003c\/td\u003e\n\u003ctd\u003e\u003ca href=\"https:\/\/heaterandspaparts.com.au\/products\/diffuser-xp-ctx-bx-large\"\u003e40071B — large\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003eNote the Viron split: the \u003cstrong\u003eXT P320\u003c\/strong\u003e uses this small diffuser (40071A), while the \u003cstrong\u003eXT P520\u003c\/strong\u003e uses the large 40071B. As with the impellers, the two Viron XT pumps do not share this part.\u003c\/p\u003e\n\n\u003ch3\u003eConfirmed Compatibility\u003c\/h3\u003e\n\u003cp\u003eAstralpool lists 40071A as the small diffuser for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCTX 180, 280, 360 and 400\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eViron XT P320\u003c\/strong\u003e and P320 C XT\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBX and E-series\u003c\/strong\u003e pumps (small)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eP280 \/ P300\u003c\/strong\u003e family\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIf your pump is a CTX 500 or 610, or a Viron XT P520, you need the \u003ca href=\"https:\/\/heaterandspaparts.com.au\/products\/diffuser-xp-ctx-bx-large\"\u003elarge diffuser 40071B\u003c\/a\u003e instead.\u003c\/p\u003e\n\n\u003ch3\u003eRelated Parts\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e40165\u003c\/strong\u003e — diffuser retaining screws (x2)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"https:\/\/heaterandspaparts.com.au\/products\/astral-65mm-oring\"\u003e78104\u003c\/a\u003e\u003c\/strong\u003e — diffuser o-ring (\u003ca href=\"https:\/\/heaterandspaparts.com.au\/products\/astral-65mm-oring\"\u003ebuy here\u003c\/a\u003e)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e40060F\u003c\/strong\u003e — impeller, CTX 360 \/ P280 \/ P320 eVo (\u003ca href=\"https:\/\/heaterandspaparts.com.au\/products\/impeller-p280-p320-fx290-e290\"\u003ebuy here\u003c\/a\u003e)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e40060X\u003c\/strong\u003e — impeller, Viron XT P320 (\u003ca href=\"https:\/\/heaterandspaparts.com.au\/products\/astralpool-p320-xt-impeller\"\u003ebuy here\u003c\/a\u003e)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e75508 \/ PS3868\u003c\/strong\u003e — mechanical seal, BX \/ TX \/ CX \/ E \/ CTX (\u003ca href=\"https:\/\/heaterandspaparts.com.au\/products\/3-4-mechanical-seal\"\u003ebuy here\u003c\/a\u003e)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e40065\u003c\/strong\u003e — basket (\u003ca href=\"https:\/\/heaterandspaparts.com.au\/products\/astralpool-hurlcon-pump-strainer-basket-tx-cx-ctx-p280-eco-e-series\"\u003ebuy here\u003c\/a\u003e)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e40089\u003c\/strong\u003e — lid complete with o-ring (\u003ca href=\"https:\/\/heaterandspaparts.com.au\/products\/complete-lid-assembly-for-astralpool-hurlcon-pumps-ctx-cx-tx-e-viron-xt-also-aquatight\"\u003ebuy here\u003c\/a\u003e)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhen to Replace\u003c\/h3\u003e\n\u003cp\u003eReplace the diffuser if it is cracked, if the sealing face against the seal plate is distorted, or if the vane passages are damaged. A cracked or poorly seated diffuser lets water bypass the impeller, which shows up as reduced flow and pressure even with a good impeller fitted. The diffuser o-ring should be replaced at the same time.\u003c\/p\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eHow do I know if I need the small or large diffuser?\u003c\/strong\u003e\u003cbr\u003eMatch your pump model. CTX 180-400, the Viron XT P320, and smaller BX \/ E-series pumps use this small 40071A. CTX 500, CTX 610 and the Viron XT P520 use the large 40071B.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the Viron XT P520 use this diffuser?\u003c\/strong\u003e\u003cbr\u003eNo. The XT P520 uses the large 40071B. Only the smaller XT P320 uses this small 40071A.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eShould I replace the o-ring too?\u003c\/strong\u003e\u003cbr\u003eYes. The diffuser o-ring, 78104, should go in with a new diffuser.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this a genuine Astralpool part?\u003c\/strong\u003e\u003cbr\u003eYes. We are an authorised Astralpool and Fluidra dealer and warranty agent.\u003c\/p\u003e\n\n\u003ch3\u003eManufacturer Catalogues, Diagrams \u0026amp; Part Numbers\u003c\/h3\u003e\n\u003cp\u003eNeed exploded views, spare part numbers, product numbers or diagrams? See the manufacturer catalogue: \u003ca href=\"https:\/\/hasp.com.au\/pages\/Astralpool_Catalogue_2026\"\u003eAstralpool Catalogue 2026\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eBefore ordering:\u003c\/strong\u003e confirm this part is correct for your pump. Use the catalogue above, seek professional assistance, or \u003ca href=\"mailto:info@hasp.com.au\"\u003econtact us\u003c\/a\u003e with photos of your existing part, model details, serial numbers and any labels. As with all products, this must be diagnosed and fitted by a qualified and experienced person. This is a \u003ca href=\"https:\/\/heaterandspaparts.com.au\/policies\/refund-policy\" rel=\"noopener\" target=\"_blank\"\u003especial-order\u003c\/a\u003e item.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eCommon search terms: Astralpool 40071A, SP40071A, CTX diffuser small, Viron XT P320 diffuser, BX diffuser, E-series diffuser, Astral Hurlcon diffuser small.\u003c\/em\u003e\u003c\/p\u003e\n\u003c!-- HASP-FLP-1.0 end | canary: diffuser-small-echo --\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"How do I know if I need the small or large diffuser?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Match your pump model. CTX 180-400, the Viron XT P320, and smaller BX and E-series pumps use this small 40071A. CTX 500, CTX 610 and the Viron XT P520 use the large 40071B.\"}},{\"@type\":\"Question\",\"name\":\"Does the Viron XT P520 use this diffuser?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No. The XT P520 uses the large 40071B. Only the smaller XT P320 uses this small 40071A.\"}},{\"@type\":\"Question\",\"name\":\"Should I replace the o-ring too?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes. The diffuser o-ring, 78104, should go in with a new diffuser.\"}},{\"@type\":\"Question\",\"name\":\"Is this a genuine Astralpool part?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes. We are an authorised Astralpool and Fluidra dealer and warranty agent.\"}}]}]}\n\u003c\/script\u003e","brand":"FLUIDRA","offers":[{"title":"Default Title","offer_id":46836099940541,"sku":"SP40071A","price":12.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0372\/5253\/files\/astralpool-diffuser-small-bx-ctx-180-400-e-series-40071a-pool-pump-parts-327.webp?v=1784679689","url":"https:\/\/heaterandspaparts.com.au\/zh-hans\/products\/sp-bx-ctx-e-diffuser-small","provider":"Heater and Spa Parts","version":"1.0","type":"link"}