How to Install a Sediment Filter for Well Water (Big Blue & Rusco)
Sediment Filters
How to Install a Sediment Filter for Well Water (Big Blue & Rusco)
Where the filter goes, how to mount both styles, and the orientation mistake that ruins spin-down filters. From a family company that has helped thousands of well owners install their own.
New to sediment filtration? This article covers installation specifically. For sizing, filter types, and choosing the right unit, start with our Sediment Filters for Well Water: The Complete Guide.
TL;DR: The Short Answer
A whole-house sediment filter installs on the main water line after the pressure tank and before any treatment equipment (acid neutralizer, iron filter, or water softener). A 20" Big Blue cartridge filter mounts to the wall with a heavy-duty bracket: mark four holes, drill, anchor, mount, then plumb. A Rusco spin-down filter is inline and supported entirely by the pipe, so there is no bracket and no drilling. Both use 1-inch inlet and outlet connections; if your plumbing is 3/4-inch, use a reducing bushing. Either filter must be mounted vertically so sediment collects at the bottom. If the sediment filter is the only thing you are installing, it is a fair DIY job for a homeowner comfortable with basic plumbing.
- Where a sediment filter goes in the treatment train
- Can you install it yourself? (30-second check)
- Big Blue vs. Rusco: installation differences
- Installing the 20" Big Blue (wall-mounted)
- Installing the Rusco spin-down (inline)
- The orientation rule everyone gets wrong
- Common installation mistakes
- Maintenance after the install
- FAQ
Where a Sediment Filter Goes in the Treatment Train
Sediment filters are almost always the first piece of equipment in line. Their job is to trap sand, silt, rust, and grit before it reaches the control valves and media tanks of your other equipment. A few grains of sand in a softener or iron filter valve can score the seals and pistons, and that is an expensive repair for a problem a $145 to $195 filter prevents.
Never install a sediment filter before the pressure tank. The pressure switch and tank need an unrestricted line from the pump. Pick your spot on the main line after the tank, where you have wall space (for a Big Blue) or a solid run of pipe (for a Rusco).
Can You Install It Yourself?
Honest answer from thousands of these installs: if the sediment filter is the only thing going in, it is one of the simplest jobs in water treatment. One cut into the main line, two threaded connections, and either four wall anchors (Big Blue) or nothing at all (Rusco). Where people get in trouble is bundling it into a full system install without planning the layout first.
Big Blue vs. Rusco: Installation Differences at a Glance
| Installation Factor | 20" Big Blue Cartridge Filter | Rusco Spin-Down (Inline) |
|---|---|---|
| Mounting | Wall-mounted with heavy-duty bracket (included) | None. Supported by the plumbing itself |
| Drilling required | Yes: 4 holes. Concrete walls need a hammer drill | No drilling |
| Weight when full | Roughly 10 to 15 lbs plus water; must be anchored solidly | Light; the pipe carries it easily |
| Connections | 1" inlet and outlet | 1" FNPT inlet and outlet |
| 3/4" plumbing? | Use a 1" x 3/4" reducing bushing | Use a 1" fitting with a reducing bushing |
| Filtration level | 5 microns (about the diameter of a human hair) | 100-mesh reusable screen (larger particles) |
| Ongoing cost | Replacement cartridge every 4 to 6 months | None. Flush the chamber and reuse the screen |
| Price | $195 with bracket, wrench & cartridge | $145 |
The trade-off is maintenance versus filtration level. The Big Blue catches much finer particles (down to 5 microns) but needs a cartridge change every 4 to 6 months, and there is a cost each time. The Rusco never needs a cartridge: when the collection chamber fills, you put a bucket under it, open the red-handled valve, and household pressure blows the sediment out in a couple of seconds. For a deeper comparison of filter types, see our best sediment filter guide and the decision guide.
Installing the 20" Big Blue (Wall-Mounted)
The 20" Big Blue kit ships with the 4x20 sump, a 5-micron cartridge, the mounting bracket, four screws, and the sump wrench you will need for cartridge changes. It is super heavy duty and built to last, but that also means it is the heavier of the two filters, so the bracket has to be anchored well.
- Pick your spot after the pressure tank. You need wall space directly behind the main line, plus clearance below the housing: the sump drops straight down for cartridge changes, so leave at least 3 to 4 inches under it.
- Hold the bracket against the wall and mark the four holes with a Sharpie or pencil.
- Drill the holes. Wood studs: standard drill and wood screws. Concrete or block: a hammer drill with a concrete bit, then insert the anchors. The concrete takes a little time, but do not skip the anchors; this housing weighs 10 to 15 pounds before you add water.
- Mount the filter and check that it is sturdy. Grab the housing and try to rock it. If it moves, fix that before you plumb anything. A wobbly filter works threaded joints loose over time.
- Do your plumbing. The inlet and outlet are 1-inch. On 3/4-inch plumbing, thread in a 1" x 3/4" reducing bushing. Watch the flow arrow on the cap so water enters the inlet side.
Installing the Rusco Spin-Down (Inline)
The Rusco inline filter is the easy one. There is no bracket, no straps, and no drilling. It is fairly light, and it hangs in the line supported entirely by the pipe.
- Pick your spot after the pressure tank on a solid, well-supported run of pipe.
- Cut in and fit the connections. The Rusco has a 1-inch FNPT inlet and outlet. If you have 1-inch plumbing you are good to go; you may just need to transition from PVC to a CPVC fitting to thread into the filter. On 3/4-inch plumbing, thread a 1-inch fitting into the filter and use a reducing bushing down to 3/4-inch.
- Orient it vertically with the clear collection chamber pointing straight down (more on this below).
- Test the flush. Once pressurized, put a bucket under the chamber and crack the red-handled valve. Household pressure should blow the chamber clean in about two seconds. That is the whole maintenance routine.
The Orientation Rule Everyone Gets Wrong
A spin-down filter must be mounted vertically, chamber down. Not horizontally, not at an angle. Here is why: the filter works by centrifugal force. It spins the incoming water, which throws sand and grit outward and drops it into the collection chamber at the bottom. Mount it sideways and there is no "bottom" for the sediment to settle into; it just churns through the screen and the filter barely works.
The same logic applies to the Big Blue: the housing hangs vertically from its cap so the cartridge sits evenly in the sump and the sump can drop straight down for changes. If your pipe run forces a horizontal filter body, rework the plumbing with a couple of elbows instead of tilting the filter. Two 1-inch elbows cost a few dollars; a filter that does not filter costs you a fouled control valve later.
Common Installation Mistakes
- Installing before the pressure tank. The filter goes after the tank, always.
- Mounting the spin-down horizontally. Centrifugal separation needs the chamber pointing down.
- Skipping wall anchors on concrete. Tapcon-style screws into crumbly block without anchors will loosen. Use the anchors, use a hammer drill.
- No clearance under the Big Blue sump. You need room to drop the sump for cartridge changes. Tight against a shelf or floor means disassembling plumbing every change.
- Forcing 3/4-inch pipe onto 1-inch ports without a proper reducing bushing. Use the right fittings for your pipe. Mismatched improvised fittings are the number one source of drips.
- No bucket plan for the flush valve. Point the Rusco's flush valve somewhere a bucket fits. You will be opening it regularly.
Maintenance After the Install
How often you service the filter depends entirely on how much sediment your well produces. If you are not sure how bad your sediment problem is, our article on sand and sediment in well water covers causes and warning signs.
| Sediment Load | Rusco Spin-Down | Big Blue Cartridge |
|---|---|---|
| Light sediment | Flush every 6 to 12 months | Replace cartridge every 6 months |
| Moderate sediment | Flush every few weeks | Replace cartridge every 4 to 6 months |
| Heavy sediment | Flush weekly | Replace cartridge monthly or pair with an upstream spin-down |
With heavy sediment, the smart setup is both filters: the Rusco first as a workhorse catching the coarse material (flush it weekly, costs nothing), then the Big Blue polishing down to 5 microns behind it. Cartridges last far longer when a spin-down does the heavy lifting. Curious what the micron numbers actually mean? See sediment filter micron ratings explained.
Frequently Asked Questions
Where should a sediment filter be installed on a well water system?
On the main line after the pressure tank and before any treatment equipment such as an acid neutralizer, iron filter, or water softener. Sediment filters are the first piece of equipment in line so they protect the valves and tanks downstream.
Can I install a whole-house sediment filter myself?
If the sediment filter is the only thing you are installing, it is a fair DIY job for anyone comfortable cutting and joining pipe. The Rusco inline filter needs no bracket or drilling at all. The Big Blue requires mounting a bracket with four screws, and a hammer drill if the wall is concrete. If you are unsure, call Aidan at 800-460-5810 and he will talk you through your specific layout.
Does a sediment filter go before or after the pressure tank?
After the pressure tank, always. The pump and pressure switch need an unrestricted line to the tank. Installing a filter before the tank can interfere with pressure regulation and starve the pump cycle.
What if my plumbing is 3/4-inch instead of 1-inch?
Both the Big Blue and the Rusco have 1-inch connections. Thread a 1-inch fitting into the filter and use a 1" x 3/4" reducing bushing to step down to your pipe size. It is a standard fitting available at any hardware store.
Can a spin-down sediment filter be mounted horizontally?
No. Spin-down filters separate sediment using centrifugal force and gravity, so the collection chamber must point straight down. Mounted horizontally, sediment cannot settle into the chamber and the filter loses most of its effectiveness. Re-route the pipe with elbows instead of tilting the filter.
How often do I flush or replace a sediment filter?
It depends on your sediment load. Light sediment: flush a spin-down every 6 to 12 months, or replace a cartridge every 6 months. Heavy sediment: you may flush a spin-down weekly, and cartridges will clog fast, which is why heavy-sediment wells often run a spin-down first and a cartridge filter second.
Should I put a second sediment filter after my treatment system?
It is optional but a good idea. If a media tank ever fails and heaves filter media into the line, a post-filter catches it before it spreads through your household plumbing. Most homes only need the pre-filter, but the post-filter is cheap insurance.