Size it by flow, not by the size of the house. The Standard 1 inch ($145) is rated 1 to 25 gallons a minute and fits 3/4 and 1 inch plumbing. The Large 2 inch ($249) is rated 18 to 100 gallons a minute and needs at least 18 gallons a minute before the water spins; below that it is a bigger housing, not a better filter. If your pump and plumbing move more than 25 gallons a minute, or your main is 1.5 or 2 inch, get the Large. Otherwise, the Standard. Not sure? Text Aidan a photo of the line coming off your pressure tank at 443-277-2204.

If you have treatment tanks, we recommend both: the two do different jobs. The 5 micron Big Blue goes first after the pressure tank and keeps fine sediment out of the softener, neutralizer or iron filter. The Rusco goes last, after the tanks, and catches media a tank lets past, such as softener resin beads or neutralizer granules, before it reaches your faucets and appliances. To check whether you need sediment filtration at all, lift the lid of the toilet tank you use most and look at the bottom.

Leave the 60 mesh screen it ships with: about 250 microns, a .010 inch opening. It stops sand, grit and rust flakes. Rusco makes polyester screens for the same housing from 24 mesh (711 microns) to 1000 mesh (15 microns), and we stock 140, 500 and 1000 mesh. A finer screen fills faster and still does not reach 5 microns, so fine silt is better handled by a 5 micron Big Blue cartridge after the pressure tank. More: sediment filter micron ratings.

When you see a layer of sediment in the bottom of the clear bowl. How often that is depends on how much sediment your well sends; the bowl tells you, not a calendar. Put a bucket under the red valve, open it, and household pressure flushes it out in about 2 seconds. No shutoff, no tools. The flush comes out hard, so a short hose from the valve to a floor drain or sump works better than a bucket.

That is its job at the end of the line. If a tank's distributor wears out, or a pressure surge or air pocket pushes media out, resin beads or neutralizer and carbon granules can travel into the house. The Rusco sits after the last tank, and its 60 mesh screen holds anything bigger than about 250 microns in the clear bowl, where you can see it. Media in the bowl is a sign to have that tank checked: flush it and text Aidan a photo at 443-277-2204.

It mounts straight up and down with the clear bowl pointing at the floor, because the sediment has to fall to the bottom of the bowl for the spin to work. It cannot go sideways or upside down. The pipe holds it up; there is no bracket. Water enters one side of the head, spins down through the bowl and leaves the other side.

We recommend one. It is an inlet and an outlet, with no drain line and no electricity, so it is about an hour or two of a plumber's time. Aidan supports your plumber by phone at 800-460-5810. If you have done some plumbing and would rather do it yourself, you can; text Aidan at 443-277-2204 with any questions.

Rusco rates the 1 inch for 1 to 25 gallons a minute and publishes a pressure loss curve for each size: the loss rises with flow, and it rises as sediment loads the screen, which is why you flush when the bowl shows a layer. If your pump and plumbing move more than 25 gallons a minute, that is the Large 2 inch, rated 18 to 100.

Rusco warrants its parts to the original purchaser for 12 months from the original sale, and repairs or replaces parts found defective, returned at the customer's expense. Rusco says using tools on it voids the warranty: hand tighten only. New, unopened items can be returned to us within 30 days of delivery with our approval first; a 25% restocking fee applies and you pay the return freight. Full terms: our refund policy.