{"product_id":"viqua-f4-plus-uv-system","title":"Viqua F4 Plus Monitored UV System","description":"\u003cdiv class=\"product-description-seo\"\u003e\n\u003ch2\u003eViqua F4 Plus Monitored UV System (VIQUA 650687)\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eViqua F4 Plus\u003c\/strong\u003e is the high-flow, \u003cstrong\u003esensor-monitored\u003c\/strong\u003e whole-house UV disinfection system in VIQUA's Professional family. It delivers \u003cstrong\u003e36 GPM at VIQUA's standard 30 mJ\/cm2 dose\u003c\/strong\u003e, \u003cstrong\u003e27 GPM at the 40 mJ\/cm2 NSF\/EPA-equivalent dose\u003c\/strong\u003e, and \u003cstrong\u003e45 GPM at the 16 mJ\/cm2 US Public Health dose\u003c\/strong\u003e (all ratings at 95% UVT, 20 C, end of lamp life). That is double the flow of the \u003ca href=\"\/products\/viqua-vh410-uv-system\"\u003eViqua VH410\u003c\/a\u003e at the same 30 mJ\/cm2 dose, which makes the F4 Plus the right chamber for large homes with 1 inch plumbing, multiple simultaneous showers, or light commercial demand.\u003c\/p\u003e\n\n\u003ch3\u003eWhat \"Monitored\" Actually Means\u003c\/h3\u003e\n\u003cp\u003eMost residential UV systems, including the VH410, run open-loop: the controller counts lamp hours and assumes the lamp is putting out enough UV. The F4 Plus closes that loop. A specialized \u003cstrong\u003e254 nm UV intensity sensor\u003c\/strong\u003e (VIQUA part 650703) reads the actual germicidal output inside the chamber and notifies you when UV performance changes, whether that is from lamp aging, a fouled quartz sleeve, or a drop in water clarity. The monitored platform also supports an optional \u003cstrong\u003esolenoid shutoff valve\u003c\/strong\u003e (VIQUA part 650717-002) that physically stops water flow if UV output falls below safe levels, so compromised water never reaches your taps.\u003c\/p\u003e\n\n\u003ch3\u003eAn Honest Note on Certification\u003c\/h3\u003e\n\u003cp\u003eThe F4 Plus is \u003cstrong\u003enot NSF\/ANSI 55 certified\u003c\/strong\u003e. If a lab test has confirmed coliform or E. coli in your well and you want third-party validated disinfection performance, buy an NSF\/ANSI 55 Class A system instead: the \u003ca href=\"\/products\/viqua-vh410-uv-system\"\u003eViqua VH410\u003c\/a\u003e (up to 18 GPM peak, 14 GPM at its certified 40 mJ\/cm2 dose) or a VIQUA PRO series system (PRO20 at 20 GPM, PRO30 at 30 GPM Class A). The F4 Plus is the value play for a different buyer: a large home that needs \u003cstrong\u003emore flow than the VH410 can deliver\u003c\/strong\u003e without stepping up to PRO series pricing, and that wants real-time sensor verification rather than a paper certificate. For supplemental, insurance-level disinfection on big plumbing it is an excellent fit. Dose for dose it still delivers 27 GPM at the same 40 mJ\/cm2 the NSF Class A standard is built around; it simply has not been through the NSF validation process.\u003c\/p\u003e\n\n\u003ch3\u003eBuilt Like the Commercial Gear It Came From\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e304 stainless steel chamber, 44.25 in x 4 in\u003c\/strong\u003e, with 1 inch MNPT inlet and outlet.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBacklit LCD controller\u003c\/strong\u003e (VIQUA part 650733R-001, 8.5 x 6 x 3 in) simultaneously displays lamp life remaining and UV intensity status, with an audible and visual lamp replacement reminder and on-board troubleshooting instructions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-output Sterilume lamp\u003c\/strong\u003e rated for 9,000 hours (about 12 months) of consistent UV output. Replacement lamp is VIQUA 602807; quartz sleeve is 602734. Both remain stocked by VIQUA.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety lamp plug\u003c\/strong\u003e: the lamp cannot be powered outside the chamber, so nobody can accidentally expose their eyes or skin to germicidal UV during service.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e100-240V, 50\/60 Hz, 130W\u003c\/strong\u003e draw. Maximum operating pressure 125 psi. Influent water temperature 36-104 F. Ships at 18 lbs.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eUV Is the Last Stage, and It Needs Clean Water\u003c\/h3\u003e\n\u003cp\u003eUV disinfection does not remove iron, hardness, sediment, sulfur, or chemicals. It inactivates microorganisms, and only if the UV light can actually reach them. The F4 Plus must be installed as the \u003cstrong\u003efinal stage\u003c\/strong\u003e of your treatment train, after any iron filter, acid neutralizer, water softener, and sediment filtration. VIQUA's water quality prerequisites for this chamber: \u003cstrong\u003ehardness below 7 grains per gallon, iron below 0.3 mg\/L, tannins below 0.1 mg\/L\u003c\/strong\u003e, with a \u003cstrong\u003e5-micron sediment prefilter\u003c\/strong\u003e ahead of the chamber. Water outside those specs coats the quartz sleeve and shadows the lamp; the difference with the F4 Plus is that the intensity sensor will actually tell you when that happens instead of failing silently.\u003c\/p\u003e\n\n\u003ch3\u003eMaintenance: One Lamp a Year\u003c\/h3\u003e\n\u003cp\u003eReplace the lamp every 9,000 hours (roughly every 12 months, and the controller reminds you). Lamp changes require no special tools: depressurize, let the unit cool 10 minutes, swap the lamp, and clean the quartz sleeve with a mild acid like vinegar or CLR while you are in there. Replace the sleeve if it cannot be cleaned or is scratched. Note that the NSF-certified PRO series runs 2-year lamps; the F4 Plus is an annual-lamp platform, which is part of why it costs less up front.\u003c\/p\u003e\n\n\u003ch3\u003eWho Should Buy This System\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBuy the F4 Plus if:\u003c\/strong\u003e your home or small business needs more than 18 GPM of disinfected flow, your water is already pre-treated to the specs above, and you want sensor-verified UV performance with an optional fail-safe shutoff.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBuy the \u003ca href=\"\/products\/viqua-vh410-uv-system\"\u003eVH410\u003c\/a\u003e instead if:\u003c\/strong\u003e a lab has confirmed coliform or E. coli and you want NSF\/ANSI 55 Class A validated performance, and your peak demand is 18 GPM or less.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAsk us about the PRO series if:\u003c\/strong\u003e you want both NSF Class A certification and high flow (PRO20, PRO30) and the budget supports it.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eNot sure which chamber fits your water and your plumbing? Start with a \u003ca href=\"\/products\/well-water-test-kit\"\u003ewell water test\u003c\/a\u003e, or read the \u003ca href=\"\/blogs\/guides\/uv-water-filter-complete-guide\"\u003ecomplete UV water filter guide\u003c\/a\u003e and our \u003ca href=\"\/blogs\/faqs\/uv-water-filter-well-water\"\u003eUV for well water FAQ\u003c\/a\u003e. Then call or text Aidan at \u003cstrong\u003e800-460-5810\u003c\/strong\u003e with your test results and peak flow numbers, and he will tell you honestly whether you need this system, the VH410, or something else entirely.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eFree shipping. 7-day-a-week support from real water treatment specialists with 30+ years of experience.\u003c\/strong\u003e Browse the full \u003ca href=\"\/collections\/ultraviolet-uv-water-disinfection-systems\"\u003eUV water disinfection collection\u003c\/a\u003e.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Mid Atlantic Water","offers":[{"title":"Default Title","offer_id":54190527676700,"sku":"VIQUA-F4-PLUS","price":2495.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0278\/9523\/4605\/files\/viqua-f4-plus-monitored-uv-system-36-gpm.jpg?v=1781046994","url":"https:\/\/midatlanticwater.net\/products\/viqua-f4-plus-uv-system","provider":"Mid Atlantic Water","version":"1.0","type":"link"}