Only if your water test shows low pH, hard water and bacteria, and you want the carbon stage for taste, odor or farm chemicals. If your test shows something else, buy something else:

Same problems, 1 to 4 people on water up to about 15 grains: the 48,000 grain version of this package ($5,975).

Low pH and hard water, no bacteria: the 2.5 neutralizer + 64,000 grain softener package ($3,495); the carbon tank ($1,995) can be added on its own.

Iron, orange stains or a strong rotten egg smell: a package with an iron filter. With bacteria too, the 5-stage iron + UV package ($5,995, 1 or 2 people) or the 6-stage package with carbon and UV ($8,295).

City water: this is the wrong system; start with a whole house carbon filter.

Send Aidan your test (call 800-460-5810 or text 443-277-2204) and he will tell you which stages you need. No test yet? Our well water test kit is $199.

The sediment filter goes first so sand and silt never reach the tanks. The neutralizer goes before the softener because calcite adds 3 to 6 grains per gallon of hardness as it raises the pH, and the softener removes it. The carbon tank comes next, and the UV light goes last: it needs clear water with iron under 0.3 ppm and hardness under 7 grains, and bacteria can grow in a carbon bed, so the UV treats the water on its way out to the house.

It removes leftover tastes and odors, a light rotten egg smell, and farm chemicals that can reach groundwater, such as herbicides and pesticides, and many VOCs. It does not remove iron, hardness, bacteria or nitrate.

It also reduces PFAS, but it is not certified for PFAS; for a PFAS result on your test, look at our PFAS removal system.

It is optional. The tank needs no drain and no electricity, and the carbon lasts about 5 years.

We recommend one, ideally a plumber who has installed water treatment before. It is the biggest kind of install we sell: five stages in a set order, three mineral tanks to load, a drain line for the softener and a GFCI outlet for the UV light. Aidan's figure for a two-tank job is 3 to 4 hours of a plumber's time; five stages take longer. 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.

Every tank ships empty. The five 50 lb boxes of calcite, the softener resin and the 2.5 cubic feet of Centaur carbon ship separately and are loaded at install through the included funnel, and the UV lamp ships in its own tube and goes into the chamber at install. The Big Blue kit comes with one 5 micron cartridge. Not included: drain tubing, pipe, fittings, adapters, salt and the GFCI outlet for the UV. Shipping is free to the lower 48 states, and the package can arrive in more than one shipment. For the current ship date, text Aidan at 443-277-2204 before you order.

Every 4 to 6 months: a new sediment cartridge ($55).

Once a year: a new UV lamp ($170).

Salt for the softener, as it runs low.

Every 30 to 36 months: 1 to 2 boxes of calcite ($145 a box).

About every 5 years: new carbon (two 1 cubic foot bags at $295 each, plus a 1/2 cubic foot that Aidan prices by text).

The Maintenance tab has each step.

Bought separately at today's prices, the five stages cost $6,875: the Big Blue kit $195, the 2.5 neutralizer $1,495, the 64,000 grain softener $2,195, the 2.5 carbon tank $1,995 and the VIQUA VH410 UV light $995. The package is $6,175, which saves $700.