The VH410 kills bacteria, including coliform and E. coli, as the water flows past the lamp. VIQUA says its UV systems are capable of inactivating common waterborne pathogens, including Cryptosporidium (chlorine-resistant), Giardia, pathogenic E. coli, hepatitis A, norovirus, Legionella, Salmonella, and Campylobacter, with efficacy demonstrated in its internal testing. It achieves this through UV-C light at 254 nanometers, which scrambles microbial DNA on contact. VIQUA rates the VH410 at 18 GPM at its standard 30 mJ/cm² dose and 14 GPM at 40 mJ/cm².

Aidan recommends the VH410 for most well homes, whether there are two people or ten: with bacteria, he says, it is never overkill. VIQUA rates it at 18 GPM at its standard dose (14 at 40 mJ/cm²), so it won't really cut down your flow or create a big pressure drop. The Viqua VH200 (9 GPM, $895) is the shorter unit for a tight space. The VH410 costs $100 more and is rated for double the flow.

Every 12 months, when the controller's 365-day countdown reaches zero and it starts to chirp (every two years for a seasonal home, per VIQUA). VIQUA rates the lamp at 9,000 hours and designs it for steady UV output over that life, then asks for a new one every year to keep the protection continuous. The replacement is the genuine VIQUA S410RL-HO lamp, $170, and changing it needs no special tools.

Yes. VIQUA requires a 5-micron sediment filter upstream of the UV chamber. It catches particulates that could shadow bacteria from the UV light. If your water has iron above 0.3 ppm, hardness above 7 grains per gallon, or any visible cloudiness, you need to address those issues before adding UV. Iron fouls the quartz sleeve within weeks, and turbidity creates shadows where bacteria survive. Clean water first, then UV as the final disinfection step.

We recommend one. It is an inlet and an outlet, the 5-micron sediment filter ahead of it and a nearby outlet, with no drain line: about an hour for a plumber for the UV alone, and an electrician only if there is no outlet near the line. VIQUA asks for the UV on the cold line before any branch, a GFCI-protected outlet, and clearance equal to the chamber's length so the lamp can be pulled out, and recommends metal fittings and at least 10 inches of copper pipe on the outlet. Aidan supports your plumber by phone at 800-460-5810. If you'd rather do it yourself, you can; text Aidan at 443-277-2204 with any questions.

The VH200 delivers 9 GPM of UV-treated water and is the shorter unit for a tight space ($895, 17.75 inch chamber). The VH410 delivers 18 GPM, double the capacity, and is the one Aidan recommends for most well homes ($995, 23.5 inch chamber). VIQUA rates both at the same doses: 9 and 18 GPM at its standard 30 mJ/cm² dose, 7 and 14 GPM at 40 mJ/cm². Both use the same BA-ICE-CL controller and the same combo ports (¾" FNPT or 1" MNPT). The VH410 lamp is $170 and the VH200 lamp is $165. For a detailed comparison, see our Viqua VH200 vs VH410 guide.

No. UV is a disinfection technology -- it kills living organisms but does not physically remove anything from the water. It has no effect on iron, manganese, sediment, chemicals, heavy metals, hardness, or taste and odor. If your water has these issues in addition to bacteria, you need separate treatment for each problem. The typical treatment sequence is: sediment filter → acid neutralizer (if pH is low) → iron filter → water softener (if needed) → UV system.